PubMed Health⌕ Search

Biomedical subjects

S Shivaji

Publications and source records attributed to S Shivaji.

At least 19 recordsLinked to original sources

Estrus behavior and fecal steroid profiles in the Asiatic lion (Panthera leo persica) during natural and gonadotropin-induced estrus.

In this paper the behavior of the Asiatic lion was studied during natural and gonadotropin-induced estrus in relation to fecal estradiol and progesterone concentration. The average length of estrus was 5.4 days and no significant difference was observed between natural and gonadotropin-induced estrus. Vocalization and rolling were the major estrus behavioral activities of Asiatic lions and the frequency of these activities were similar in both natural and gonadotropin-induced estrus and treatment with exogenous gonadotropin did not alter estrus behavioral activities. A significant positive correlation was observed between fecal estradiol and frequency of estrus behavior during natural and gonadotropin-induced estrus. Following gonadotropin treatment estrus could be induced in 69% of animals and these induced animals ovulated following hCG treatment. This study reports for the first time the successful use of the non-invasive fecal steroid assay for monitoring the induction of estrus and ovulation in the Asiatic lion.

Animals↗

Reclassification of Amycolatopsis orientalis DSM 43387 as Amycolatopsis benzoatilytica sp. nov.

Amycolatopsis orientalis DSM 43387, a clinical isolate from submandibular mycetoma tissue, is one of three plasmid-bearing strains of the genus Amycolatopsis. It degrades aromatic compounds such as m-hydroxybenzoate, but does not produce any antibiotics, in contrast to Amycolatopsis orientalis NBRC 12806T. Phylogenetic analysis based on a complete 16S rRNA gene sequence placed the strain in the clade of Amycolatopsis albidoflavus IMSNU 22139T, distant from the clade of A. orientalis NBRC 12806T. The strain showed low DNA-DNA hybridization values of 24.1 and 45.7 % with A. orientalis NBRC 12806T and A. albidoflavus DSM 44639T (= IMSNU 22139T), respectively. It could also be readily distinguished from A. orientalis NBRC 12806T and all species with validly published names classified in the genus Amycolatopsis, by using a combination of chemical and physiological markers such as utilization of lactose, degradation of xanthine, hypoxanthine, gelatin and casein and hydrolysis of Tween 80, indicating that it represents a novel species. Strain DSM 43387 could also be differentiated from A. orientalis NBRC 12806T and its nearest neighbour A. albidoflavus IMSNU 22139T on the basis of fatty acid and phospholipid profiles. Based on genotypic and phenotypic differences, the name Amycolatopsis benzoatilytica sp. nov. is proposed for strain DSM 43387 that was previously classified as Amycolatopsis orientalis. The type strain is AK 16/65T (= DSM 43387T = ATCC 55165T = IMRU 1389T).

Actinomycetales↗

Clostridium schirmacherense sp. nov., an obligately anaerobic, proteolytic, psychrophilic bacterium isolated from lake sediment of Schirmacher Oasis, Antarctica.

A novel obligately anaerobic, proteolytic bacterium, designated AP15T, was isolated from lake sediments of Schirmacher Oasis, Antarctica. The bacterium produced maximum cell mass between 5 and 10 degrees C in an anaerobic basal medium containing 0.5 % tryptone and peptone. The strain grew optimally at a pH around 8.0 and tolerated NaCl up to a concentration of 7.5 %. It contained diphosphatidylglycerol as the major phospholipid and C(15 : 0), C(16 : 0) and C(17 : 0) as the major cellular fatty acids. Several amino acids, including arginine, leucine, isoleucine, cysteine, glutamate and serine, supported growth. Glutamate was degraded to acetate, propionate, CO2 and H2. In addition, the strain degraded carbohydrates including glucose, raffinose, adonitol, ribose and rhamnose. The main fermentation products during growth on glucose were H2, CO2, formate, acetate, propionate and isovalerate. The DNA G+C content of the bacterium was 24 mol%. On the basis of a phylogenetic analysis, strain AP15(T) is identified as a close relative of Clostridium subterminale ATCC 25774T, with which it shares 99.5 % similarity at the 16S rRNA gene sequence level; however, it exhibits a low DNA-DNA binding value (55 %) to this strain at the whole-genome level. In addition to showing other major differences with respect to C. subterminale and other members of the genus Clostridium, AP15T also exhibits phenotypic differences. On the basis of these differences, strain AP15T is identified as representing a novel species of the genus Clostridium, for which the name Clostridium schirmacherense sp. nov. is proposed. The type strain is AP15T (=DSM 17394T = JCM 13289T).

Amino Acids↗

Bacillus aerius sp. nov., Bacillus aerophilus sp. nov., Bacillus stratosphericus sp. nov. and Bacillus altitudinis sp. nov., isolated from cryogenic tubes used for collecting air samples from high altitudes.

Four novel bacterial strains were isolated from cryogenic tubes used to collect air samples at altitudes of 24, 28 and 41 km. The four strains, 24K(T), 28K(T), 41KF2a(T) and 41KF2b(T), were identified as members of the genus Bacillus. Phylogenetic analysis based on 16S rRNA gene sequences indicated that three of the strains, 24K(T), 28K(T) and 41KF2a(T), are very similar to one another (>98 % sequence similarity) and show a similarity of 98-99 % with Bacillus licheniformis and 98 % with Bacillus sonorensis. DNA-DNA hybridization studies showed that strains 24K(T), 28K(T) and 41KF2a(T) exhibit <70 % similarity with each other and with B. licheniformis and B. sonorensis. Differences in phenotypic and chemotaxonomic characteristics between the novel strains and B. licheniformis and B. sonorensis further confirmed that these three isolates are representatives of three separate novel species. Strain 41KF2b(T) showed 100 % 16S rRNA gene sequence similarity to Bacillus pumilus, but differed from its nearest phylogenetic neighbour in a number of phenotypic and chemotaxonomic characteristics and showed only 55 % DNA-DNA relatedness. Therefore, the four isolates represent four novel species for which the names Bacillus aerius sp. nov. (type strain, 24K(T)=MTCC 7303(T)=JCM 13348(T)), Bacillus aerophilus sp. nov. (type strain, 28K(T)=MTCC 7304(T)=JCM 13347(T)), Bacillus stratosphericus sp. nov. (type strain, 41KF2a(T)=MTCC 7305(T)=JCM 13349(T)) and Bacillus altitudinis sp. nov. (type strain, 41KF2b(T)=MTCC 7306(T)=JCM 13350(T)) are proposed.

Air Microbiology↗

Rubrivivax benzoatilyticus sp. nov., an aromatic, hydrocarbon-degrading purple betaproteobacterium.

A brown-coloured bacterium was isolated from photoheterotrophic (benzoate) enrichments of flooded paddy soil from Andhra Pradesh, India. On the basis of 16S rRNA gene sequence analysis, strain JA2(T) was shown to belong to the class Betaproteobacteria, related to Rubrivivax gelatinosus (99 % sequence similarity). Cells of strain JA2(T) are Gram-negative, motile rods with monopolar single flagella. The strain contained bacteriochlorophyll a and most probably the carotenoids spirilloxanthin and sphaeroidene, but did not have internal membrane structures. Intact cells had absorption maxima at 378, 488, 520, 590, 802 and 884 nm. No growth factors were required. Strain JA2(T) grew on benzoate, 2-aminobenzoate (anthranilate), 4-aminobenzoate, 4-hydroxybenzoate, phthalate, phenylalanine, trans-cinnamate, benzamide, salicylate, cyclohexanone, cyclohexanol and cyclohexane-2-carboxylate as carbon sources and/or electron donors. The DNA G+C content was 74.9 mol%. Based on DNA-DNA hybridization studies, 16S rRNA gene sequence analysis and morphological and physiological characteristics, strain JA2(T) is different from representatives of other photosynthetic species of the Betaproteobacteria and was recognised as representing a novel species, for which the name Rubrivivax benzoatilyticus sp. nov. is proposed. The type strain is JA2(T) (=ATCC BAA-35(T)=JCM 13220(T)=MTCC 7087(T)).

Base Composition↗

Exiguobacterium indicum sp. nov., a psychrophilic bacterium from the Hamta glacier of the Himalayan mountain ranges of India.

Strain HHS 31(T), a Gram-positive, motile, rod-shaped, non-spore-forming, alkaliphilic bacterium, was isolated from the melt water of a glacier. Phenotypic and chemotaxonomic characteristics indicate that strain HHS 31(T) is related to species of the genus Exiguobacterium. The 16S rRNA gene sequence similarities between HHS 31(T) and strains of known species confirm that it is closely related to members of the genus Exiguobacterium (93-99 %) and that it exhibits >97 % similarity with Exiguobacterium acetylicum DSM 20416(T) (98.9 %), Exiguobacterium antarcticum DSM 14480(T) (98.0 %), Exiguobacterium oxidotolerans JCM 12280(T) (97.9 %) and Exiguobacterium undae DSM 14481(T) (97.4 %). Phylogenetic analysis based on the 16S rRNA gene sequence further confirms the affiliation of HHS 31(T) with the genus Exiguobacterium. However, the levels of DNA-DNA relatedness between HHS 31(T) and E. oxidotolerans JCM 12280(T), E. acetylicum DSM 20416(T), E. undae DSM 14481(T) and E. antarcticum DSM 14480(T) are 50, 63, 67 and 28 %, respectively. Strain HHS 31(T) also differs from these four closely related species in terms of a number of phenotypic traits. The phenotypic, chemotaxonomic and phylogenetic data suggest that HHS 31(T) merits the status of a novel species, for which the name Exiguobacterium indicum sp. nov. is proposed. The type strain is HHS 31(T) (=LMG 23471(T)=IAM 15368(T)).

Bacillaceae↗

Semen characteristics of the captive Indian white-backed vulture (Gyps bengalensis).

The present paper describes, to our knowledge for the first time, the successful collection and evaluation of semen from the Indian white-backed vulture (Gyps bengalensis), a critically endangered bird. Over a period of 2 yr, semen was collected using the manual massage method and evaluated for semen volume, semen pH, sperm concentration, percentage normal/abnormal spermatozoa, and percentage motile spermatozoa. It appears that the concentration of spermatozoa and percentage motile spermatozoa in the Indian white-backed vultures are low compared to those in other birds. Tyrode medium supplemented with albumin, lactate, and pyruvate (TALP) proved to be the best semen extender compared to two others (Beltsville Poultry Semen Extender and Lake diluent). Furthermore, TALP with 20% egg yolk and supplemented with 8% dimethyl sulfoxide maintained 50% of the initial percentage of motile spermatozoa following cryopreservation and thawing. A computer-aided semen analysis indicated that the spermatozoa of the Indian white-backed vulture are extremely active and swim in linear trajectories for up to 5 h following dilution in TALP. The trajectories were linear with time, but we noticed a decrease in the velocity parameters (average path velocity, curvilinear velocity, and progressive velocity). Thus, the present study provides baseline data on semen characteristics of the highly endangered Indian white-backed vulture, and these data could be of immense importance to reproductive and conservation biologists attempting to breed these animals in captivity, which to date has not been achieved.

Animals↗

Novelty of the pyruvate metabolic enzyme dihydrolipoamide dehydrogenase in spermatozoa: correlation of its localization, tyrosine phosphorylation, and activity during sperm capacitation.

Spermatozoa are cells distinctly different from other somatic cells of the body, capacitation being one of the unique phenomena manifested by this gamete. We have shown earlier that dihydrolipoamide dehydrogenase, a post-pyruvate metabolic enzyme, undergoes capacitation-dependent tyrosine phosphorylation, and the functioning of the enzyme is required for hyperactivation (enhanced motility) and acrosome reaction of hamster spermatozoa (Mitra, K., and Shivaji, S. (2004) Biol. Reprod. 70, 887-899). In this report we have investigated the localization of this mitochondrial enzyme in spermatozoa revealing non-canonical extra-mitochondrial localization of the enzyme in mammalian spermatozoa. In hamster spermatozoa, dihydrolipoamide dehydrogenase along with its host complex, the pyruvate dehydrogenase complex, are localized in the acrosome and in the principal piece of the sperm flagella. The localization of dihydrolipoamide dehydrogenase, however, appears to be in the mitochondria in the spermatocytes, but in spermatids it appears to show a juxtanuclear localization (like Golgi). The capacitation-dependent time course of tyrosine phosphorylation of dihydrolipoamide dehydrogenase appears to be different in the principal piece of the flagella and the acrosome in hamster spermatozoa. Activity assays of this bi-directional enzyme suggest a strong correlation between the tyrosine phosphorylation and the bi-directional enzyme activity. This is the first report of a direct correlation of the localization, tyrosine phosphorylation, and activity of the important metabolic enzyme, dihydrolipoamide dehydrogenase, implicating dual involvement and regulation of the enzyme during sperm capacitation.

Acrosome↗

The vascular endothelial growth factor (VEGF) +405G>C 5'-untranslated region polymorphism and increased risk of endometriosis in South Indian women: a case control study.

BACKGROUND: Vascular endothelial growth factor (VEGF), a major mediator of angiogenesis and vascular permeability, is known to play a key role in the pathophysiology of endometriosis. METHODS AND RESULTS: The single nucleotide polymorphisms, -460C>T and +405G>C, in the 5'-untranslated region of the VEGF gene were tested for association in a case-control study of 215 affected women and 210 women with no evidence of disease. All the women were of South Indian origin and ascertained from the same infertility clinic. The genotype and allele frequencies of the -460C>T polymorphism did not differ significantly between cases and controls. In contrast, the genotype (P = 0.002) and allele (P = 0.001) frequencies of the +405G>C polymorphism showed a significant difference between cases and controls. The +405 GG genotype was found more often in patients with an endometrioma >3 cm compared to controls. The frequency of the -460T/+405C haplotype (P = 0.016) was significantly lower in affected women compared to controls. CONCLUSIONS: The -460T/+405C haplotype in the VEGF gene, which is associated with lower promoter activity, was significantly less common in women with endometriosis than in controls. These data suggest that the +405G allele may influence the likelihood of a woman developing the disease.

5' Untranslated Regions↗

GSTM1, GSTT1 and CYP1A1 detoxification gene polymorphisms and their relationship with advanced stages of endometriosis in South Indian women.

OBJECTIVE(S): Studies on association between endometriosis and various phase I and phase II detoxification genes such as glutathione S-transferase M1 and theta 1 (GSTM1 and GSTT1) and cytochrome P450 (CYP1A1) have produced inconsistent results possibly because of ethnic differences. The present study was undertaken to investigate the frequency of the CYP1A1 (6235T>C) polymorphism and GSTM1, GSTT1 null mutations in a South Indian women's population with and without endometriosis. METHODS: The frequencies of variants were studied in 310 women with laparoscopically proven endometriosis (rAFS III=101; IV=209) and 215 women without endometriosis using the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: The GSTM1 null deletion showed significant association (P=0.028) with endometriosis. No significant difference was found in the frequencies of the GSTT1 null deletion in cases and controls. The frequencies of the variant CYP1A1 homozygous and heterozygous alleles in the cases were 9% and 44.2% against 14.4% and 42.3% in the controls. Further, we observed a considerable difference in the GSTM1 null deletion frequency in this population when compared with other populations of the world. CONCLUSIONS: We observed an association between endometriosis and the GSTM1 null deletion, but not with GSTT1 null deletions or the CYP1A1 MspI polymorphism in South Indian women.

Adolescent↗

Hexachlorocyclohexane-degrading bacterial strains Sphingomonas paucimobilis B90A, UT26 and Sp+, having similar lin genes, represent three distinct species, Sphingobium indicum sp. nov., Sphingobium japonicum sp. nov. and Sphingobium francense sp. nov., and reclassification of [Sphingomonas] chungbukensis as Sphingobium chungbukense comb. nov.

Three strains of Sphingomonas paucimobilis, B90A, UT26 and Sp+, isolated from different geographical locations, were found to degrade hexachlorocyclohexane. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these strains do not fall in a clade that includes the type strain, Sphingomonas paucimobilis ATCC 29837(T), but form a coherent cluster with [Sphingomonas] chungbukensis IMSNU 11152(T) followed by Sphingobium chlorophenolicum ATCC 33790(T). The three strains showed low DNA-DNA relatedness values with Sphingomonas paucimobilis ATCC 29837(T) (8-25%), [Sphingomonas] chungbukensis IMSNU 11152(T) (10-17%), Sphingobium chlorophenolicum ATCC 33790(T) (23-54%) and Sphingomonas xenophaga DSM 6383(T) (10-28%), indicating that they do not belong to any of these species. Although the three strains were found to be closely related to each other based on 16S rRNA gene sequence similarity (99.1-99.4%), DNA-DNA relatedness (19-59%) and pulsed-field gel electrophoresis (PFGE) patterns indicated that they possibly represent three novel species of the genus Sphingobium. The three strains could also be readily distinguished by biochemical tests. The three strains showed similar polar lipid profiles and contained sphingoglycolipids. The strains differed from each other in fatty acid composition but contained the predominant fatty acids characteristic of other Sphingobium species. A phylogenetic study based on 16S rRNA gene sequences showed that [Sphingomonas] chungbukensis IMSNU 11152(T) formed a cluster with members of the genus Sphingobium. Based on these results, it is proposed that strains B90A, UT26 and Sp+, previously known as Sphingomonas paucimobilis, are the type strains of Sphingobium indicum sp. nov. (=MTCC 6364(T)=CCM 7286(T)), Sphingobium japonicum sp. nov. (=MTCC 6362(T)=CCM 7287(T)) and Sphingobium francense sp. nov. (=MTCC 6363(T)=CCM 7288(T)), respectively. It is also proposed that [Sphingomonas] chungbukensis be transferred to Sphingobium chungbukense comb. nov.

Bacterial Proteins↗

Planococcus stackebrandtii sp. nov., isolated from a cold desert of the Himalayas, India.

The taxonomic position of a bacterium isolated from a cold desert of the Himalayas, India, was analysed by using a polyphasic approach. The isolated strain, designated K22-03T, had phenotypic characteristics that matched those of the genus Planococcus and it represents a novel species. The almost-complete 16S rRNA gene sequence (1464 bases) of the novel strain was compared with those of previously studied Planococcus type strains and confirmed that the strain belongs to the genus Planococcus. 16S rRNA gene sequence analysis indicated that strain K22-03T differs from all other species of Planococcus by at least 2.5 %. DNA-DNA hybridization showed that it had low genomic relatedness with Planomicrobium mcmeekinii (MTCC 3704T, 23 %), Planococcus psychrophilus (MTCC 3812T, 61 %), Planococcus antarcticus (MTCC 3854T, 45 %) and Planomicrobium okeanokoites (MTCC 3703T, 51 %), the four species with which it was most closely related based on 16S rRNA gene sequence analysis (97-97.5 % similarity). Therefore, strain K22-03T should be recognized as a novel species, for which the name Planococcus stackebrandtii sp. nov. is proposed. The type strain is K22-03T (=MTCC 6226T=DSM 16419T=JCM 12481T).

Bacterial Typing Techniques↗

Marinomonas ushuaiensis sp. nov., isolated from coastal sea water in Ushuaia, Argentina, sub-Antarctica.

A Gram-negative, rod-shaped, psychrophilic, motile, non-spore-forming bacterium, strain U1T, was isolated from Ushuaia located at the southernmost tip of Argentina. On the basis of 16S rRNA gene sequence similarity, strain U1T was found to be closely related to Marinomonas communis (DSM 5604T) and Marinomonas primoryensis (IAM 15010T). At the DNA-DNA level, however, the values for similarity were 41 and 25 %, respectively. The major fatty acids present were iso-C(16 : 0), C(16 : 1)omega7c, iso-C(17 : 1) and C(18 : 1)omega7c and the G+C content of the DNA was 43.6 mol%. All of the above characteristics support the affiliation of strain U1T to the genus Marinomonas. Furthermore, on the basis of phenotypic features, chemotaxonomic characteristics and phylogenetic analysis of the 16S rRNA gene sequence, it appears that strain U1T is distinct from the four Marinomonas species with validly published names. Strain U1T, therefore, represents a novel species, for which the name Marinomonas ushuaiensis sp. nov. is proposed. The type strain of M. ushuaiensis is U1T (=MTCC 6143T=DSM 15871T=JCM 12170T).

Antarctic Regions↗

Bacillus arsenicus sp. nov., an arsenic-resistant bacterium isolated from a siderite concretion in West Bengal, India.

Strain Con a/3(T) is a Gram-positive, motile, endospore-forming, rod-shaped and arsenic-resistant bacterium, which was isolated from a concretion of arsenic ore obtained from a bore-hole. The bacterium grew in the presence of 20 mM arsenate and 0.5 mM arsenite. Diaminopimelic acid was present in the cell wall peptidoglycan, MK-7 was the major menaquinone, and iso-C(15 : 0), anteiso-C(15 : 0), iso-C(16 : 0) and C(16 : 1)(delta7cis) were the major fatty acids. Based on its phenotypic, chemotaxonomic and phylogenetic characteristics, strain Con a/3(T) was identified as a member of the genus Bacillus. It exhibited maximum similarity (97 %) at the 16S rRNA gene level with Bacillus barbaricus (DSM 14730(T)); however, the DNA-DNA relatedness value with B. barbaricus was 60 %. Strain Con a/3(T) also exhibited a number of phenotypic differences from B. barbaricus (DSM 14730(T)). Strain Con a/3(T) was therefore identified as representing a novel species of the genus Bacillus, for which the name Bacillus arsenicus sp. nov. is proposed. The type strain is Con a/3(T) (= MTCC 4380(T) = DSM 15822(T) = JCM 12167(T)).

Anti-Bacterial Agents↗

Marinobacter maritimus sp. nov., a psychrotolerant strain isolated from sea water off the subantarctic Kerguelen islands.

A psychrotolerant, Gram-negative, motile bacterium, designated CK 47(T), was isolated from sea water off the subantarctic Kerguelen islands (50 degrees 40' S 68 degrees 25' E). The isolate grew optimally at 22 degrees C and minimum and maximum temperature of growth were 4 and 37 degrees C, respectively. It required Na(+) for growth and exhibited optimum growth at pH 8.5 and 4% NaCl. It utilized hexane, heptane and petroleum ether as sole sources of carbon. Strain CK 47(T) had Q9 as the major respiratory quinone and C(16 : 0) (21.7%), C(17:0) (21.3%), C(18:0) (5.7%), C(18:1)omega7c (9.0%) and C(18:1)omega9c (31.4%) as predominant fatty acids. The G+C content of the DNA was 58 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that CK 47(T) formed a coherent cluster within the genus Marinobacter. It exhibited highest 16S rRNA gene sequence similarity of 96.8% with Marinobacter lipolyticus. However, the level of DNA-DNA relatedness between strain CK47(T) and M. lipolyticus was only 55%. On the basis of phenotypic characteristics, and phylogenetic and genotypic distinctiveness, strain CK 47(T) is considered to represent a novel species of the genus Marinobacter. The name Marinobacter maritimus sp. nov. is proposed, with CK 47(T) (=JCM 12521(T)=MTCC 6519(T)) as the type strain.

Alteromonadaceae↗

Pedobacter himalayensis sp. nov., from the Hamta glacier located in the Himalayan mountain ranges of India.

Strain HHS 22(T) was isolated from a glacial water sample from the snout of the Hamta glacier located in the Himalayan mountain ranges of India. Phenotypic, chemotaxonomic and phylogenetic analyses established the affiliation of the isolate to the genus Pedobacter. HHS 22(T) exhibits high 16S rRNA gene sequence similarity with Pedobacter cryoconitis (98 %). However, the level of DNA-DNA relatedness between HHS 22(T) and P. cryoconitis is only 42 %. Furthermore, HHS 22(T) differs from P. cryoconitis and the four other recognized species of Pedobacter in a number of phenotypic characteristics. These data suggest that HHS 22(T) represents a novel species of the genus Pedobacter, for which the name Pedobacter himalayensis sp. nov. is proposed. The type strain is HHS 22(T) (= JCM 12171(T) = MTCC 6384(T)).

Bacterial Typing Techniques↗

Dyadobacter hamtensis sp. nov., from Hamta glacier, located in the Himalayas, India.

Strain HHS 11(T) was isolated from a water sample collected from the snout of Hamta glacier located in the Himalayan mountain ranges of India. Phenotypic, chemotaxonomic and phylogenetic analyses established the affiliation of the isolate to the genus Dyadobacter. HHS 11(T) possessed 96 and 95% 16S rRNA gene sequence similarity with respect to Dyadobacter crusticola and Dyadobacter fermentans, respectively. Furthermore, strain HHS 11(T) differs from D. crusticola and D. fermentans in a number of phenotypic characteristics. These data suggest that strain HHS 11(T) represents a novel species of the genus Dyadobacter, for which the name Dyadobacter hamtensis sp. nov. is proposed. The type strain is HHS 11(T) (=JCM 12919(T)=MTCC 7023(T)).

Bacterial Typing Techniques↗

Proteins implicated in sperm capacitation.

Spermatozoa after being deposited in the female reproductive tract spend a considerable time in this foreign environment prior to fertilization of the oocyte. Chang and Austin independently observed1,2 that this time spent by the spermatozoa in the female tract is not consequential but a necessary event in the life cycle of the male gamete, and Austin2 first called this maturation period of spermatozoa as 'Capacitation'. Ever since, attempts have been made to understand and unravel the molecular mechanism of capacitation. Based on the results obtained so far, it is clear that capacitation is guided by novel signal transduction pathways influencing varied aspects of spermatozoa. Capacitation could be, thus, defined as the cumulative molecular, cellular and physiological changes that occur in spermatozoa in the female reproductive tract to achieve the final competence to fertilize the oocyte. This review is structured so as to first understand the key features of capacitation and then to survey the players which bring about these changes during capacitation.

Animals↗