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Biomedical subjects

C L Moore

Publications and source records attributed to C L Moore.

At least 55 records · Page 3Linked to original sources
PubMed1992

Copulatory behavior, reproduction, and sperm competition in two strains of male rats.

Long-Evans males fathered 72% of the offspring when one Long-Evans and one F344 male mated repeatedly with the same female throughout her estrus. When each male was restricted to one ejaculation and the second male was allowed to begin mating immediately following the first male's ejaculation, the second male left more offspring in each strain. However, the proportion was significantly greater for Long-Evans males. In contrast, there were no strain differences in either number of pregnancies or litter size in noncompetitive matings limited to two ejaculations, the minimal number required to induce pregnancy. The only consistent behavioral differences were the greater number of intromissions performed with shorter latencies by F344 males, differences that cannot readily be used to explain their reduced success. It was hypothesized that the two strains may differ in the adequacy of penile reflexes used to form, set, or dislodge sperm plugs.

Animals↗
PubMed1992

The role of maternal stimulation in the development of sexual behavior and its neural basis.

Both sexual differentiation, which is a matter of individual development, and sexual dissimilation, which is a matter of individual differences, result from developmental processes that are open to input from the early maternal environment. There are reliable features in both the dam and the young that ensure that males receive more perineal stimulation from maternal licking than is necessary for survival and normal growth. This stimulation contributes toward the development of masculine sexual behavior and mechanisms in the central nervous system that control copulatory reflexes. Because of differences in signals that they produce, males receive more stimulation than females. This bias in early stimulation accounts for some of the dissimilarity between the sexes in nervous system morphology and behavior. The same processes that produce sex differences can also produce individual differences among males. These differences are likely to have significant functional consequences in rats, a species in which males have a high level of intrasexual reproductive competition. Future research will be directed toward testing this functional hypothesis and toward exploring the extent of stimulative effects on the development of the sexually dimorphic brain regions that function in sexual behavior.

Afferent Pathways↗
PubMed1991

Point mutations upstream of the yeast ADH2 poly(A) site significantly reduce the efficiency of 3'-end formation.

The sequences directing formation of mRNA 3' ends in Saccharomyces cerevisiae are not well defined. This is in contrast to the situation in higher eukaryotes in which the sequence AAUAAA is known to be crucial to proper 3'-end formation. The AAUAAA hexanucleotide is found upstream of the poly(A) site in some but not all yeast genes. One of these is the gene coding for alcohol dehydrogenase, ADH2. Deletion or a double point mutation of the AAUAAA has only a small effect on the efficiency of the reaction, and in contrast to the mammalian system, it is most likely not operating as a major processing signal in the yeast cell. However, we isolated point mutations which reveal that a region located approximately 80 nucleotides upstream of the poly(A) site plays a critical role in either transcription termination, polyadenylation, or both. These mutations represent the first point mutations in yeasts which significantly reduce the efficiency of 3'-end formation.

Alcohol Dehydrogenase↗
PubMed1988

Components required for in vitro cleavage and polyadenylation of eukaryotic mRNA.

We have studied in vitro cleavage/polyadenylation of precursor RNA containing herpes simplex virus type 2 poly A site sequences and have analyzed four RNA/protein complexes which form during in vitro reactions. Two complexes, A and B, form extremely rapidly and are then progressively replaced by a third complex, C which is produced following cleavage and polyadenylation of precursor RNA. Substitution of ATP with cordycepin triphosphate prevents polyadenylation and the formation of complex C however a fourth complex, D results which contains cleaved RNA. A precursor RNA lacking GU-rich downstream sequences required for efficient cleavage/polyadenylation fails to form complex B and produces a markedly reduced amount of complex A. As these GU-rich sequences are required for efficient cleavage, this establishes a relationship between complex B formation and cleavage/polyadenylation of precursor RNA in vitro. The components required for in vitro RNA processing have been separated by fractionation of the nuclear extract on Q-Sepharose and Biorex 70 columns. A Q-Sepharose fraction forms complex B but does not process RNA. Addition of a Biorex 70 fraction restores cleavage activity at the poly A site but this fraction does not appear to contribute to complex formation. Moreover, in the absence of polyethylene glycol, precursor RNA is not cleaved and polyadenylated, however, complexes A and B readily form. Thus, while complex B is necessary for in vitro cleavage and polyadenylation, it may not contain all the components required for this processing.

Base Sequence↗
PubMed1988

Two proteins crosslinked to RNA containing the adenovirus L3 poly(A) site require the AAUAAA sequence for binding.

The major proteins crosslinked by UV light to RNA containing the adenovirus-2 L3 poly(A) site are species of 155, 68 and 38 kd mol. wt (p155, p68 and p38). Mutation of AAUAAA to AAGAAA prevented cross-linking of the two larger proteins and destroyed the ability of the RNA to compete for binding of these proteins. However, association of p155 and p68 with precursor was unaffected by deletion of sequences downstream of the poly(A) site critical for in vitro polyadenylation. These two proteins are in the polyadenylation-specific, but not the nonspecific complexes detected by electrophoresis in nondenaturing gels. In addition, p155 and p68 are not found on RNA which has been processed. p155 bound a 15-nt oligomer containing AAUAAA, and thus does not require extended RNA sequence for interaction with RNA. Identified by immunoprecipitation with specific antibody, p38 is the C protein of heterogeneous ribonucleoprotein particles (hmRNPs). While p155 has an Sm epitope, it is not associated with snRNPs containing trimethylated guanosine caps.

Adenosine Triphosphate↗
PubMed1988

Sedimentation analysis of polyadenylation-specific complexes.

Precursor RNA containing the adenovirus L3 polyadenylation site is assembled into a 50S complex upon incubation with HeLa nuclear extract at 30 degrees C. The cofactor and sequence requirements for 50S complex formation are similar to those of the in vitro polyadenylation reaction. Assembly of this complex requires ATP but is not dependent upon synthesis of a poly(A) tract. In addition, a 50S complex does not form on substrate RNA in which the AAUAAA hexanucleotide upstream of the poly(A) site has been mutated to AAGAAA or on RNA in which sequences between +5 and +48 nucleotides downstream of the site have been removed. These mutations also prevent in vitro processing of substrate RNA. Kinetic studies suggest that the 50S complex is an intermediate in the polyadenylation reaction. It forms at an early stage in the reaction and at later times contains both poly(A)+ RNA as well as unreacted precursor. U-type small nuclear ribonucleoprotein particles are components of the 50S complex, as shown by immunoprecipitation with antiserum specific to the trimethyl cap of these small nuclear RNAs.

Adenoviruses, Human↗
PubMed1987

Electrophoretic separation of polyadenylation-specific complexes.

A polyadenylation-specific complex composed of precursor RNA containing the adenovirus-2 L3 site and HeLa cellular components was detected by electrophoresis on a native, low-percentage polyacrylamide gel. Upon incubation in a reaction containing ATP and nuclear extract, precursor RNA was rapidly assembled into this complex. This assembly did not require poly(A) synthesis, as it occurred efficiently in the presence of ATP analogs that inhibited this reaction. Mutation of the hexanucleotide AAUAAA 20 nucleotides upstream of the L3 site to AAGAAA or deletion of sequence between +5 and +48 nucleotides downstream of the L3 site inactivates polyadenylation. The specific complex did not effectively from on substrate RNA with either the AAGAAA mutation or the downstream deletion mutation. Kinetic experiments showed that the assembly of this complex preceded processing of precursor RNA. We proposed that formation of this complex represents an intermediate step in polyadenylation.

Adenoviruses, Human↗
PubMed1986

Prenatal stress affects mother-infant interaction in Norway rats.

Pregnant Long-Evans rats were stressed by crowding, and subsequent mother-infant interactions were described after cross-fostering. Prenatally stressed pups elicited less maternal licking from unstressed foster dams than controls, and previously stressed dams licked unstressed foster pups less than controls. No other differences in mother-infant interactions were detected. Adult offspring reared by foster dams that were stressed during pregnancy were more active in an open field than controls, but prenatally stressed and unstressed animals reared by control dams did not differ. Thus, stress during pregnancy can alter the maternal behavior of stressed dams, and the differential maternal stimulation can affect adult open-field behavior. Because prenatally stressed pups elicit different maternal care, cross-fostering does not eliminate the possibility that maternal stimulation may mediate some prenatal stress effects.

Animals↗
PubMed1986

Behavioral responses of infant rats to maternal licking: variations with age and sex.

Behavioral interactions of Norway rat pups and their dams during maternal anogenital licking (AGL) were observed. Regularities in posture and orientation that may facilitate AGL were noted, and age-related changes in the pup's postural adjustments that may contribute to the decline of AGL in the 3rd postpartum week were described. It was found that cutaneous stimulation of the perineum, such as that provided by AGL, stimulates a characteristic leg extension response from pups. It was concluded that this response, which includes immobility and extension of all limbs, may permit maternal licking to continue long enough to stimulate the pup to eliminate and to allow the dam to ingest the urine. Males and females were found to exhibit similar responses and similar age-related changes. However, the latency from onset of AGL to performance of the leg extension response was shorter in males.

Age Factors↗
PubMed1986

Analysis of RNA cleavage at the adenovirus-2 L3 polyadenylation site.

Processing at the L3 polyadenylation site of human adenovirus-2 involves endonucleolytic cleavage generating the 3' terminal sequence -UAOH to which adenosine residues are added. This dinucleotide is 19 nucleotides downstream of the AAUAAA polyadenylation signal. The ATP analog cordycepin triphosphate (3' dATP) inhibits poly(A) synthesis, but precursor RNA is processed to give a product terminating in -UAAH. Addition of only one adenosine analog demonstrates that the initial poly(A) tract is synthesized by polymerization of single residues rather than by ligation of preformed poly(A). Cleavage is not coupled to polyadenylation since incubation with an ATP analog containing a non-hydrolyzable alpha--beta bond generates a product with a 3' terminus coincident with the -UAOH) addition site. Addition of this accurately processed RNA to a nuclear extract results in efficient polyadenylation, suggesting that downstream sequences are not required for synthesis of the poly(A) tract. Finally, processing at the L3 poly(A) site may involve both endonucleolytic and exonucleolytic activities.

Adenoviruses, Human↗
PubMed1986

Depletion of brain mitochondria cytochrome oxidase in the mottled mouse mutant.

The mouse mutant Mobr is an animal model of Menkes kinky hair syndrome with a similar defect in copper utilization. The copper-dependent enzyme, cytochrome oxidase from the brain, liver, and heart mitochondria was examined. The brain and heart from Mobr/y had significantly less cytochrome alpha + alpha 3 than normal animals' when the cytochrome absorption spectra of tissue samples from animals 11 to 13 days of age were analyzed. Liver cytochrome was not significantly different. When brain mitochondrial cytochrome oxidase spectrograms from animals of different ages were examined, a major change was found to occur during the 2nd week of life. When cytochrome oxidase activity from brain mitochondria was measured, assaying the rate of oxidation of cytochrome c, the results were similar to those from spectrogram analysis.

Animals↗
PubMed1986

A hormonal basis for sex differences in the self-grooming of rats.

The self-grooming behavior of prepubescent male and female rats is described. Sex differences were observed in components of grooming addressed to the genitals, but not in other aspects of grooming. A hormonal basis for the sex difference was examined in two experiments. When females were injected with testosterone propionate (TP) on the day of birth, their subsequent grooming was found to be no different from that of control-treated females. However, males and females gonadectomized at weaning and treated daily with TP each performed significantly more genital self-grooming than oil-treated controls. There were no sex differences in gonadectomized, oil-treated rats, and sex differences in response to TP were limited to greater responsiveness of females to a 50-micrograms, but not 200-micrograms, TP dose. These results lead to the conclusion that sex differences in self-grooming can be accounted for primarily by differences in testosterone availability during the peripubertal period.

Animals↗
PubMed1986

Prenatal stress eliminates differential maternal attention to male offspring in Norway rats.

Maternal licking behavior was observed in 20 Long-Evans rat dams on two consecutive days. Stimulus pups were male and female foster pups from dams that were either housed with 5 adult males during the last trimester of pregnancy (stressed) or housed alone (unstressed). Unstressed male pups received significantly more maternal licking than their female siblings, but prenatally stressed males and females received similar levels of maternal licking, comparable to that directed to unstressed females. In a second study, urine collected from prenatally stressed male pups elicited significantly less investigation from dams in a choice test than urine from age-matched unstressed males. It is concluded that the chemosignals which stimulate dams normally to provide more maternal attention to male than female neonates are deficient in prenatally stressed males. The results raise the possibility that differential maternal care may mediate some effects of prenatal stress on behavioral development in males.

Animals↗
PubMed1986

Sex differences in self-grooming of rats: effects of gonadal hormones and context.

When prepubescent males and females were placed alone in a novel cage, males were found to groom their genitals, but not other body regions, more than females. This sex difference was present in untreated and in testosterone-treated gonadectomized rats as well as in intact rats. Neither the presence of gonads nor testosterone treatment affected grooming in this context. However, when similarly treated rats of the same age were observed in groups in the home cage, no sex difference in genital grooming of intact or gonadectomized rats was found. Testosterone significantly increased nongenital grooming in both sexes and genital grooming in males. Thus, both the presence of sex differences and the effects of testosterone on self-grooming depend on the behavioral context.

Animals↗
PubMed1985

Accurate cleavage and polyadenylation of exogenous RNA substrate.

Purified precursor RNA containing the L3 polyadenylation site of late adenovirus 2 mRNA is accurately cleaved and polyadenylated when incubated with nuclear extract from HeLa cells. The reaction is very efficient; 75% of the precursor is correctly processed. Cleavage is rapidly followed by polymerization of an initial poly(A) tract of approximately 130 nucleotides. Additional adenosine residues are added during further incubation. In the presence of the ATP analog alpha-beta-methylene-adenosine 5' triphosphate, the precursor RNA is cleaved but not polyadenylated, suggesting that processing is not coupled to the synthesis of the initial poly(A) tract. In the absence of free Mg2+, a small RNA of approximately 46 nucleotides is stabilized against degradation. Fingerprint analysis suggests this RNA is produced by endonucleolytic cleavage at the L3 site. Like the in vitro splicing reaction, the in vitro polyadenylation reaction is inhibited by adding antiserum against the small nuclear ribonucleoprotein particle containing U1 RNA.

Adenosine Triphosphate↗