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M Baez

Publications and source records attributed to M Baez.

At least 37 records · Page 2Linked to original sources
PubMed1994

5-hydroxytryptamine2A, 5-hydroxytryptamine2B, and 5-hydroxytryptamine2C receptor mRNA expression in the spinal cord of rat, cat, monkey and human.

Currently three subtypes of the 5-HT2 receptor have been identified through binding studies and/or molecular biology studies, 5-HT2A, 5-HT2B, and 5-HT2C. The identification of these receptor subtypes in the spinal cord of humans and experimental animal species is incomplete. In the present study, polymerase chain reaction with Southern hybridization analysis was used to determine whether the mRNA for the 5-HT2A, 5-HT2B and 5-HT2C receptors could be detected in spinal cord tissue from rats, cats, monkeys and humans. Brain tissue from rat, cat and monkey were also examined for comparison. 5-HT2A and 5-HT2B receptor mRNAs were amplified and localized with rat 5-HT2A and 5-HT2B primers and probes, respectively, in tissue from all species. In rats, 5-HT2C receptor mRNA was amplified and localized with rat 5-HT2C primer and mouse 5-HT2C probe, respectively, while in cat, monkey, and human tissue, human 5-HT2C primers and probes were used. Spinal cord from all four species contained mRNA for the 5-HT2A receptor. Brain tissue from rat, cat and monkey also contained 5-HT2A mRNA. Spinal cord tissue from all four species contained 5-HT2B message. Brain tissue from cat and monkey contained 5-HT2B mRNA, but this was not detected in rat brain. 5-HT2C mRNA was detected in spinal cord and brain tissue from rat, monkey and human, but was only detected in brain tissue of the cat (i.e. no 5-HT2C mRNA was detected in cat spinal cord).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Functional coupling of the 5-HT2C serotonin receptor to G proteins in Xenopus oocytes.

The serotonin 2c (5-HT2C) receptor mediates its cellular effects by interacting with heterotrimeric guanine nucleotide binding proteins (G proteins). To characterize which G proteins are involved in functional coupling to the receptor, a mouse 5-HT2C receptor was expressed in Xenopus oocytes, and antisense oligoncleotides complementary to the mRNA sequence of the endogenous Xenopus G protein alpha subunits were used to inhibit G protein synthesis. Antisense oligonucleotide against the Xenopus G(o) alpha subunit inhibited the 5-HT2C receptor function, and coexpression of a rat G(o) alpha subunit reversed the inhibition by the anti-Xenopus G(o) oligonucleotide. Furthermore, antisense oligonucleotides against both the G(o) and Gi1 alpha subunits inhibited the electrophysiologic response induced by stimulation of the 5-HT2C receptor. These data suggest that both G(o) and Gi1 are involved in functional coupling of the 5-HT2C receptor to phospholipase C in Xenopus oocytes.

Animals↗
PubMed1994

Serotonin-induced contraction in canine coronary artery and saphenous vein: role of a 5-HT1D-like receptor.

The identity of the serotonin (5-HT) receptor(s) that mediate(s) contraction in canine coronary artery and saphenous vein remains controversial. Ring segments of endothelium-denuded coronary artery and helical strips of saphenous vein were suspended in organ chambers for measurement of isometric force. 5-HT, alpha Me-5-HT and sumatriptan contracted both coronary artery and saphenous vein and the non-selective 5-HT receptor antagonist 1-naphthylpiperazine (100nM) blocked 5-HT- and sumatriptan-induced contraction in both tissues. The agonist rank order potency for contraction (5-HT > sumatriptan > alpha Me5-HT > 5-MeOT > 5-MeT) was similar in both tissues and was consistent with that for a 5-HT1D receptor. Oligonucleotide primers specific for the 5-HT1D receptor sequence were designed for use in a polymerase chain reaction (PCR). cDNA derived from total RNA or mRNA from canine tissues was used in the PCR. PCR resulted in the amplification of a 632 base pair sequence in both canine coronary artery and saphenous vein; consistent with that expected for the 5-HT1D receptor. Southern blot analysis, with an oligonucleotide probe internal to the sequence amplified by the PCR primers, confirmed that the sequence amplified by PCR was the 5-HT1D receptor. Thus, the 5-HT1D receptor is expressed in canine coronary artery and saphenous vein and taken together with the pharmacological data, supports the possibility that a 5-HT1D-like receptor mediates contraction in these two tissues.

5-Methoxytryptamine↗
PubMed1994

Relationship between 5-HT2A receptor mRNA density and contractility in trachea and aorta from guinea pig and rat.

The present studies document marked differences in contractile responsiveness to serotonin in trachea and aorta between guinea pig and rat. For example, the guinea pig trachea and rat aorta markedly contract in response to serotonin via activation of 5-HT2A receptors. In contrast, the rat trachea and guinea pig aorta only modestly contract to serotonin. The availability of 5-HT2A receptor selective cDNA clones from brain of both guinea pig and rat permitted molecular probes to be designed and PCR amplification studies initiated to identify and quantify 5-HT2A receptor specific mRNA in these tissues. For trachea, 3-fold higher concentrations of 5-HT2A receptor specific mRNA were found in guinea pig relative to rat trachea. These data are consistent with the more profound contractile response to serotonin in guinea pig versus rat trachea and suggest that differences in tracheal contractility to serotonin correlate with the density of 5-HT2A receptor mRNA. In contrast, although rat aorta contracted more dramatically to serotonin than guinea pig aorta, rat aorta possessed a similar concentration of 5-HT2A receptor specific mRNA as compared to guinea pig aorta. Thus, for the aorta, differences in the concentration of 5-HT2A receptor mRNA are not sufficient to explain the observed differences in contractility between tissues from guinea pig and rat. These studies documenting 5-HT2A receptor mRNA in rat trachea and guinea pig aorta, two tissues that do not markedly contract in response to serotonin indicate that 5-HT2A receptor mRNA although present, has not resulted in a receptor capable of mediating a contractile response in these tissues.

Animals↗
PubMed1994

Disruption of potential alpha-helix in the G loop of the guinea pig 5-hydroxytryptamine2 receptor does not prevent receptor coupling to phosphoinositide hydrolysis.

Heterogeneity of the 5-hydroxytryptamine2 (5-HT2) receptor across species has been implicated in several pharmacological and physiological studies. Although 5-HT2 receptors in the rat have been linked to increases in phosphoinositide (PI) hydrolysis, little evidence exists to support the association of guinea pig 5-HT2 receptors with PI hydrolysis, the second messenger generally linked with 5-HT2 receptors. In the present study, we have taken a molecular and biochemical approach to determining whether species differences in brain 5-HT2 receptors exist between rat and guinea pig. First, we isolated partial cortical 5-HT2 receptor cDNA clones that encompassed the third intracellular loop, a receptor area putatively important in receptor-effector coupling. The amino acid sequences deduced from the cDNA clones for rat and guinea pig brain 5-HT2 receptor were 97% homologous. However, the guinea pig 5-HT2 receptor had two tandem substitutions that disrupted a potential alpha helix in the region of the third cytoplasmic loop, which theoretically could alter the intracellular coupling of the guinea pig cortical 5-HT2 receptor. Because of these molecular differences, we examined further the pharmacological activation of the brain 5-HT2 receptor from guinea pig. 5-HT and the 5-HT2 receptor agonist alpha-methyl-5-HT increased PI hydrolysis in guinea pig cortical slices whereas the 5-HT1C receptor agonist 5-methyltryptamine was significantly less potent. In addition, the 5-HT2 receptor antagonists LY53857, ketanserin, and spiperone blocked 5-HT-stimulated PI hydrolysis. These pharmacological data suggested that activation of the 5-HT2 receptor in guinea pig cortical slices was associated with PI hydrolysis. Thus, although areas of the guinea pig brain 5-HT2 receptor that influence receptor-effector coupling were different from the rat, such differences were not critical to receptor-effector coupling because, as in the rat, guinea pig brain 5-HT2 receptors were also coupled to PI hydrolysis.

Amino Acid Sequence↗
PubMed1994

Molecular cloning, functional expression, and mRNA tissue distribution of the human 5-hydroxytryptamine2B receptor.

Clones encoding a portion of the human 5-hydroxytryptamine (5-HT)2B receptor gene were isolated from a human placental genomic library. Based on distribution studies of 5-HT2B receptor mRNA, human uterus cDNA libraries were constructed and screened, resulting in the isolation of several full-length cDNA clones. These clones harbored a common single open reading frame encoding a protein of 481 amino acids. The deduced amino acid sequence of the human 5-HT2B receptor displayed 91.5% identity within the transmembrane domains and 82% identity overall with the rat 5-HT2B receptor. The human 5-HT2B receptor stably expressed in AV12-664 cells demonstrated high affinity (Kd = 10.18 +/- 1.60 nM), saturable [3H]serotonin binding, similar to that previously described for the rat 5-HT2B receptor. The pharmacological profile of the human 5-HT2B receptor was virtually identical to that of the rat 5-HT2B receptor, with the exceptions of the 5-HT2A receptor antagonists ketanserin and spiperone. Both compounds exhibited higher affinity at the human 5-HT2B receptor (ketanserin, Ki = 376 +/- 58 nM; spiperone, Ki = 697 +/- 54 nM) than at the rat 5-HT2B receptor (ketanserin, Ki = 3559 +/- 175 nM; spiperone, Ki = 3278 +/- 92 nM). Functional coupling of the human 5-HT2B receptor was also demonstrated in AV12-664 cells, where 5-HT produced a dose-dependent increase in phosphatidylinositol hydrolysis (EC50 = 27 +/- 12 nM) analogous to that seen with the rat 5-HT2B receptor. Reverse transcription-polymerase chain reaction studies revealed human 5-HT2B receptor mRNA to be expressed in many tissues, including the central nervous system. The presence of 5-HT2B receptor mRNA in human brain and not in rat brain raises the possibility that the 5-HT2B receptor may be of significance in higher brain function.

Amino Acid Sequence↗
PubMed1994

Species variations in transmembrane region V of the 5-hydroxytryptamine type 2A receptor alter the structure-activity relationship of certain ergolines and tryptamines.

Previous work has suggested that species differences in the structure-activity relationship for ergolines and tryptamines at the 5-hydroxytryptamine (5-HT)2A (formerly known as the 5-HT2) receptor are related to aliphatic substitution at the N1-position on the indole nucleus. The present work has confirmed these findings by examining the rat and human cloned 5-HT2A receptors. As previously found, N1-substitution of ergolines or tryptamines had no effect or increased affinity for the rat 5-HT2A receptor but decreased affinity for the human receptor. Also, the N1-unsubstituted analogues had higher affinity for the human 5-HT2A receptor, whereas the N1-alkyl analogues had a higher affinity for the rat receptor. By mutating the rat 5-HT2A receptor, the importance of the Ala/Ser242 species variation in amino acid sequence was examined in relation to this structure-activity relationship. Three mutations of the rat 5-HT2A receptor were made, i.e., A242S, A242V, and A242T. All three mutations resulted in functional (able to stimulate inositol phosphate hydrolysis) 5-HT2A receptors with high affinity for [3H]ketanserin and 1-(2,5-dimethoxy-4-[125I]iodophenyl)isopropylamine. The A242S mutation resulted in a pharmacological profile that was almost identical to that of the human 5-HT2A receptor but differed significantly from that of the wild-type rat receptor. This strongly suggests that the Ala/Ser242 species variation accounts for the differences in the structure-activity relationship. The A242V and A242T mutations resulted in differing but profound effects on affinity for the different ergolines and tryptamines. The results are discussed in terms of the importance of position 242 in the binding of these ligands to 5-HT2A receptors. In addition, arguments are presented that suggest that a hydrogen-bonding interaction occurs between the human 5-HT2A receptor at Ser242 and the N1-hydrogen of N1-unsubstituted ergolines and tryptamines and may serve as an important contact point in the receptor.

Amphetamines↗
PubMed1993

Ventilation and heart rate response during exercise in normals: relevance for rate variable pacing.

The observation of a close relationship of heart rate to oxygen uptake (HR-VO2) and heart rate to minute ventilation (HR-VE) has been shown to be of particular value in rate variable pacing. However, the impact of anaerobic threshold (AT) for the HR-VO2 and HR-VE slope has been studied less. Twenty-three male and 16 female subjects, mean age 52 +/- 7 years, were selected in whom complete heart catherization and extensive noninvasive studies excluded major cardiopulmonary disease. Semisupine bicycle exercise testing with analysis of respiratory gas exchange was performed using a ramping work rate protocol with work increments of 20 watts/min. At the respiratory AT, determined by the V slope method, oxygen uptake (VO2-AT) was 15.2 +/- 3.0 mL/kg in males versus 13.8 +/- 2.3 mL/kg in females and heart rate (HR-AT) was 109 +/- 18 beats/min versus 119 +/- 20 beats/min, respectively. Heart rate was highly correlated (r > or = 0.9) to VO2 and minute ventilation (VE). A linear regression for HR-VO2, however, was found only in 16/39 and for HR-VE in 11/39 subjects. Assuming the AT as the breakpoint of two linear curves, it could be demonstrated that compared to low exercise HR appeared to increase at maximal exercise more in relation to VO2 but less in relation to VE; in men the individual slopes for HR-VO2 were 2.6 +/- 0.7 below but 3.2 +/- 1.0 above AT (P < 0.05) and the slopes for HR-VE were 1.6 +/- 0.5 below but 1.0 +/- 0.4 above AT (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Anaerobic Threshold↗
PubMed1993

Pharmacological characteristics of the newly cloned rat 5-hydroxytryptamine2F receptor.

The rat 5-hydroxytryptamine (5-HT)2F (serotonin2F) receptor is a newly cloned member of the 5-HT2/1C receptor family. The pharmacology of the 5-HT2F receptor was explored using a variety of structurally different compounds in a radioligand binding assay. In addition, the 5-HT2F receptor was shown to stimulate production of inositol 1,4,5-trisphosphate in the transformed cells. Based on the affinities of the compounds tested, their known affinities for certain of the other 5-HT receptors, and the fact that activation of the cloned 5-HT2F receptor stimulates inositol 1,4,5-trisphosphate production, the 5-HT2F receptor was determined to be a novel receptor and a member of the 5-HT2/1C receptor family. In addition, several agonists and partial agonists were evaluated for contractile activity in the rat stomach fundus, and these activities were correlated with their binding affinities at the 5-HT2F receptor. A highly significant correlation was found, providing additional evidence that is consistent with the 5-HT2F receptor being the stomach fundal contractile receptor. [3H]5-HT had high affinity for this receptor both at 37 degrees and at 0 degree (Kd = 7.87 +/- 0.55 and 0.12 +/- 0.02 nM, respectively). The difference in affinity for [3H]5-HT at the two temperatures prompted an investigation of potential temperature-dependent differences in the binding affinities of agonists versus antagonists. Agonists such as 5-HT, 5-methoxytryptamine, etc., showed higher affinity for the 5-HT2F receptor at 0 degree than at 37 degrees, whereas antagonists such as methysergide, 1-naphthylpiperazine, etc., showed no difference in affinity for this receptor at the two different temperatures. Therefore, the affinity of a compound for the 5-HT2F receptor at 37 degrees versus 0 degree was shown to be useful for predicting agonist or antagonist activity. Additionally, information is provided about some of the structural requirements for the affinity of certain tryptamines at the 5-HT2F receptor.

Animals↗
PubMed1992

Molecular cloning, functional expression, and pharmacological characterization of a novel serotonin receptor (5-hydroxytryptamine2F) from rat stomach fundus.

Using the polymerase chain reaction amplification technique in conjunction with conventional cloning techniques, we have isolated a novel member of the serotonin [5-hydroxytryptamine (5-HT)] 1C/2 receptor subfamily (designated 5-HT2F) from rat stomach fundus. Two DNA fragments were amplified from cDNA synthesized from rat stomach fundus poly(A)+ RNA using the polymerase chain reaction technique with degenerate oligonucleotide primers derived from sequence comparisons of the second, third, and sixth putative transmembrane domains of known 5-HT receptors. These fragments were used as hybridization probes to isolate full length cDNA clones from rat stomach fundus cDNA libraries. Full length cDNA clones contained one open reading frame encoding a 479-amino acid protein with seven hydrophobic domains, characteristic of members of the guanine nucleotide-binding protein-coupled receptor superfamily. Within these seven putative transmembrane domains, the 5-HT2F receptor shared greatest homology with the rat 5-HT1C and 5-HT2 receptor subtypes (70% and 68%, respectively). Cell lines stably expressing the 5-HT2F receptor were established and demonstrated functional coupling to phosphatidylinositol hydrolysis upon 5-HT stimulation analagous to that observed for the 5-HT1C and 5-HT2 receptors. Membranes from the stably transfected cell lines (but not the untransfected parental lines) exhibited high affinity (Kd = 7.9 nM), saturable binding of [3H]5-HT. Maximum binding ranged from 0.1 to 2.4 pmol/mg of protein, depending on the clonal isolate. Using [3H]5-HT as the basis for a radioligand binding assay, the relative affinities of several tryptamine and piperazine derivatives for the cloned 5-HT2F receptor correlated with their relative potencies to contract the rat stomach fundus. These data suggest a probable relationship between this novel 5-HT2F receptor and the serotonin contractile receptor of the rat stomach fundus.

Amino Acid Sequence↗
PubMed1990

Pharmacological and molecular evidence that the contractile response to serotonin in rat stomach fundus is not mediated by activation of the 5-hydroxytryptamine1C receptor.

The receptor mediating contraction in response to serotonin in the rat stomach fundus has not been characterized in light of the currently acceptable serotonergic receptor classification scheme. Several biochemical and pharmacological approaches to a characterization of this receptor have demonstrated nonidentity with the 5-hydroxytryptamine2 (5HT2), 5HT3, 5HT1A, and 5HT1B receptors, as defined by radiolabeled ligand binding studies in brain cortical membranes. Although there have been reports suggesting that the receptor in the rat stomach fundus may be analogous to the 5HT1C receptor, other pharmacological and biochemical studies have not been consistent with this idea. The present study utilized high affinity ligands for the 5HT1C receptor and the recently derived 5HT1C receptor cDNA clone to provide a more definitive approach to the examination of the relationship between the 5HT1C receptor and the serotonergic contractile receptor in the rat stomach fundus. Using three ligands with high affinity at the 5HT1C receptor, LY53857, ritanserin, and SCH23390, the contractile response to serotonin was inhibited by all three ligands. However, inhibition did not appear competitive nor was the inhibitory potency of these ligands consistent with their affinity at 5HT1C binding sites in brain cortical membranes. We further showed that SCH23390, unlike LY53857 and ritanserin, was also a partial agonist, producing a maximal contraction that was approximately 50% of the maximal response to serotonin in the rat stomach fundus. Thus, the use of these ligands did not support the contention that the receptor mediating serotonin-induced contractions in the rat stomach is identical to the 5HT1C receptor. In more definitive studies using a 5HT1C receptor cDNA probe, we were unable to detect hybridization of the probe with any mRNA species from the rat stomach fundus, whereas the 5HT1C receptor cDNA probe did hybridize to the 5HT1C receptor mRNA in rat brain. Because the cathepsin-D cDNA probe hybridized equally in rat brain and stomach fundus, ensuring the integrity of the RNA preparation from both tissues, the absence of measurable quantities of the 5HT1C receptor mRNA in the rat stomach was probe specific and not an artifact. Furthermore, primers specific for the rat 5HT1C receptor sequence did not detect significant levels of receptor mRNA in rat fundus, although the target sequence was amplified a minimum of 10(5)-fold in a polymerase chain reaction. These studies do not support the contention that the receptor mediating contractile responses to serotonin in the rat stomach fundus is identical to the 5HT1C receptor.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1987

Steroid hormone regulation of the gene encoding the chicken heat shock protein hsp 108.

We have previously isolated a partial cDNA clone encoding a heat shock protein which has been termed hsp 108 (Zarucki-Schulz, T., Kulomaa, M. S., Headon, D. R., Weigel, N. L., Baez, M., Edwards, D. O., McGuire, W. L., Schrader, W. T., and O'Malley, B. W. (1984) Proc. Natl. Acad. Sci. U.S.A. 81, 6358-6362; Sargan, D. R., Tsai, M.-J., and O'Malley, B. W. (1985) Biochemistry 25, 6252-6258). Here we examine the expression of the hsp 108 gene in steroid-stimulated chick oviducts. After 16 h of secondary stimulation with estrogen or progesterone, a 20-50-fold increase in hsp 108 mRNA is detected above unstimulated levels. RNA quantitation by Rot analysis shows that in these oviducts there are 75 molecules of hsp 108 mRNA/oviduct cell. Nuclear "run-off" assays indicate only a 2-4-fold increase in the rate of transcription of the gene in response to either sex steroid, suggesting that the gene is regulated both at the transcriptional level and by mRNA stabilization. On hormone withdrawal, the concentration of hsp 108 mRNA in the oviduct falls to unstimulated control levels within 4 days. Chronic stimulation of the chicks with estrogen (or high acute doses of estrogen) attenuates specifically the inductive response of the hsp 108 gene, but not of ovalbumin, under these conditions. This is not due to a significant reduction of the transcription rate of the gene. We have previously shown that hsp 108 is expressed constitutively in many tissues of the chick (Sargan, D. R., Tsai, M.-J., and O'Malley, B. W. (1985) Biochemistry 25, 6252-6258). In tissues which are not responsive to hormones, no short-term effects of hormone administration on the gene were observed. In the spleen there is a reproducible slow activation of the gene, but the kinetics of this response suggest that it is not a primary response to the hormone. Thus, this hsp 108 gene codes for an interesting new eucaryotic heat shock protein which is regulated also by steroid hormones in a tissue-specific manner.

Animals↗
PubMed1984

Molecular cloning of a cDNA for the chicken progesterone receptor B antigen.

A cDNA for the chicken progesterone receptor B subunit antigen (Mr, 108,000) has been isolated from a cDNA library prepared from size-selected chicken oviduct poly(A)+RNA. A specific monoclonal antibody raised against hen progesterone receptor B subunit (alpha PR-B) was used to screen the library. Recombinant clones reacting with the antibody by virtue of antigen expression were used in hybrid-selected translation. A single clone, pPRB-1, hybridized specifically to a mRNA that yielded a Mr 108,000 protein when translated in vitro and which was immunoprecipitable by the alpha PR-B antibody. This cDNA represents a 470-base-pair portion of the PR-B nucleotide sequence. Additional clones have been subsequently isolated from the recombinant library using the insert from pPRB-1 as a specific probe. A mRNA size of approximately 3000 nucleotides was determined for the chicken progesterone receptor B subunit by formaldehyde/agarose gel electrophoresis and blot hybridization using pPRB-1 as a probe. Preliminary studies show that withdrawal of hormone from chickens treated chronically with estrogen leads to a dramatic decrease in the cellular RNA concentration of receptor B, indicating that target tissue levels of receptor B RNA are under hormonal control.

Animals↗
PubMed1983

Higher-order structural determinants for expression of the ovalbumin gene family.

The ovalbumin gene and the ovalbumin-related X and Y genes are expressed in the chicken oviduct in response to steroid hormones. These three genes are linked within a 100 kb domain of DNA which is preferentially sensitive to DNase I digestion in oviduct cell nuclei. No such preferential sensitivity to DNase is observed in nuclei isolated from other chicken tissues in which these genes are not transcribed. Thus, the DNase I sensitivity observed is correlated with the capacity for these genes to be expressed in oviduct. We have asked the question: are there specific signals in the DNA which are responsible for defining this domain or for conferring upon it the active, DNase I-sensitive, conformation? We have located DNA sequences belonging to a single repetitive DNA family, termed CR1, which are preferentially located in or near the boundary regions of the 100 kb domain. Therefore, these CR1 sequences are possible candidates for such a function. We have also searched for, but have not observed, any tissue-specific rearrangements of the DNA in the boundary regions of the domain. It is therefore unlikely that DNA rearrangements are involved in establishing the DNase I-sensitive domain in oviduct cells. However, we do note that a region at the far 3' end of the domain exhibits a cytidine methylation pattern which is highly variable among different chicken tissues. In particular, this region, which is approximately 30 kb downstream from the ovalbumin gene, is undermethylated in oviduct as compared to other hen tissues, and thus could be a control region involved in domain activation.

Animals↗
PubMed1980

Complete nucleotide sequence of the influenza A/PR/8/34 virus NS gene and comparison with the NS genes of the A/Udorn/72 and A/FPV/Rostock/34 strains.

The nucleotide sequence of the NS gene of the human influenza virus A/PR/8/34 was determined and found to be the same length (890 nucleotides) as the NS gene of another human influenza virus A/Udorn/72 and of the avian isolate A/FPV/Rostock/34. Comparison of the sequences of the NS genes of the two human influenza viruses shows an 8.9% difference whereas the NS gene of the avian isolate differs by only 8% from that of the human strain A/PR/8/34. The extensive sequence similarity among these three genes does not support the notion of species specific homology groups among NS genes of avian and human influenza virus strains. The primary sequence of the A/PR/8/34 NS gene is consistent with the findings that the influenza virus NS gene may code for two overlapping polypeptides. In addition, an open reading frame potentially coding for a polypeptide 167 amino acids in length was found in the negative strand RNA of the A/PR/8/34 virus NS gene.

Amino Acid Sequence↗