共查询到20条相似文献,搜索用时 15 毫秒
1.
Background
A polypeptide chain of a protein-protein complex is said to be obligatory if it is bound to another chain throughout its functional lifetime. Such a chain might not adopt the native fold in the unbound form. A non-obligatory polypeptide chain associates with another chain and dissociates upon molecular stimulus. Although conformational changes at the interaction interface are expected, the overall 3-D structure of the non-obligatory chain is unaltered. The present study focuses on protein-protein complexes to understand further the differences between obligatory and non-obligatory interfaces. 相似文献2.
3.
Mark P Green Lee D Spate Tina E Parks Koji Kimura Clifton N Murphy Jim E Williams Monty S Kerley Jonathan A Green Duane H Keisler R Michael Roberts 《Reproductive biology and endocrinology : RB&E》2008,6(1):21
Background
Evolutionary theory suggests that in polygynous mammalian species females in better body condition should produce more sons than daughters. Few controlled studies have however tested this hypothesis and controversy exists as to whether body condition score or maternal diet is in fact the determining factor of offspring sex. Here, we examined whether maternal diet, specifically increased n-6 polyunsaturated fatty acid (PUFA) intake, of ewes with a constant body condition score around the time of conception influenced sex ratio. 相似文献4.
Background
Sexual selection theory predicts that females, being the limiting sex, invest less in courtship signals than males. However, when chemical signals are involved it is often the female that initiates mating by producing stimuli that inform about sex and/or receptivity. This apparent contradiction has been discussed in the literature as 'the female pheromone fallacy'. Because the release of chemical stimuli may not have evolved to elicit the male's courtship response, whether these female stimuli represent signals remains an open question. Using techniques to visualise and block release of urine, we studied the role of urine signals during fighting and mating interactions of crayfish (Pacifastacus leniusculus). Test individuals were blindfolded to exclude visual disturbance from dye release and artificial urine introduction. 相似文献5.
Genetic homology and crossing over in the X and Y chromosomes of mammals 总被引:51,自引:4,他引:47
Paul S. Burgoyne 《Human genetics》1982,61(2):85-90
Summary The X-Y crossover model described in this paper postulates that (1) the pairing observed between the X and the Y chromosome at zygotene is a consequence of genetic homology, (2) there is a single obligatory crossover between the X and Y pairing segments, and (3) the segment of the X which pairs with the Y is protected from subsequent X inactivation. Genes distal to the proposed crossover (pseudoautosomal genes) will appear to be autosomally inherited because they will be transmitted to both male and female offspring. Some criteria for identifying pseudoautosomal genes are outlined.The existence of a single obligatory crossover between the X and Y of the mouse is strongly supported by a recent demonstration that the sex-reversing mutation Sxr, which is passed equally to XX and XY offspring by male carriers, is transmitted on the sex chromosomes. Pseudoautosomally inherited genes may also be responsible for XX sex reversal in goats and familial XX sex reversal in man. 相似文献
6.
Background
We use a simulation-based model to study the impact of female philopatry and heterogeneity of habitat quality on the evolution of primary sex ratio. 相似文献7.
Anne Jørgensen Jane E Morthorst Ole Andersen Lene J Rasmussen Poul Bjerregaard 《Reproductive biology and endocrinology : RB&E》2008,6(1):25
Background
The mechanism of sex determination in zebrafish is largely unknown and neither sex chromosomes nor a sex-determining gene have been identified. This indicates that sex determination in zebrafish is mediated by genetic signals from autosomal genes. The aim of this study was to determine the precise timing of expression of six genes previously suggested to be associated with sex differentiation in zebrafish. The current study investigates the expression of all six genes in the same individual fish with extensive sampling dates during sex determination and -differentiation. 相似文献8.
Steroid hormone receptors ERα and PR characterised by immunohistochemistry in the mare adrenal gland
Ylva Hedberg Alm Sayamon Sukjumlong Hans Kindahl Anne-Marie Dalin 《Acta veterinaria Scandinavica》2009,51(1):31
Background
Sex steroid hormone receptors have been identified in the adrenal gland of rat, sheep and rhesus monkey, indicating a direct effect of sex steroids on adrenal gland function. 相似文献9.
David C Muller Graham G Giles Julie Bassett Howard A Morris John T Manning John L Hopper Dallas R English Gianluca Severi 《Reproductive biology and endocrinology : RB&E》2011,9(1):57
Background
The second to fourth digit ratio (2D:4D) is used as a marker of prenatal sex hormone exposure. The objective of this study was to examine whether circulating concentrations of sex hormones and SHBG measured in adulthood was associated with 2D:4D. 相似文献10.
Seo Young Kim Sebastian Schneeweiss Jun Liu Gregory W Daniel Chun-Lan Chang Katie Garneau Daniel H Solomon 《Arthritis research & therapy》2010,12(4):R154
Introduction
Although osteoporosis has been reported to be more common in patients with rheumatoid arthritis (RA), little is known whether the risk of osteoporotic fractures in these patients differs by age, sex, and anatomic site. 相似文献11.
Miloš Macholán Stuart JE Baird Pavel Munclinger Petra Dufková Barbora Bímová Jaroslav Piálek 《BMC evolutionary biology》2008,8(1):271
Background
The Mus musculus musculus/M. m. domesticus contact zone in Europe is characterised by sharp frequency discontinuities for sex chromosome markers at the centre of wider clines in allozyme frequencies. 相似文献12.
Background
Ostrich (Struthio camelus) breeds have been gaining increasing significance around the world. The large-scale sex determination of chicks is an important task in the development of these breeds. To date, two PCR-based methods have been established for ostrich sex typing, neither of them intended for large-scale analyses. Here, we report on a protocol adapted to carry out large-scale gender scoring using DNA obtained from chick feathers. 相似文献13.
Anne J?rgensen John E Nielsen Jane E Morthorst Poul Bjerregaard Henrik Leffers 《Reproductive biology and endocrinology : RB&E》2009,7(1):97
Background
Investigating gonadal gene expression is important in attempting to elucidate the molecular mechanism of sex determination and differentiation in the model species zebrafish. However, the small size of juvenile zebrafish and correspondingly their gonads complicates this type of investigation. Furthermore, the lack of a genetic sex marker in juvenile zebrafish prevents pooling gonads from several individuals. The aim of this study was to establish a method to isolate the gonads from individual juvenile zebrafish allowing future investigations of gonadal gene expression during sex determination and differentiation. 相似文献14.
Background
Many genes involved in the sex determining cascade have indicated signals of positive selection and rapid evolution across different species. Even though fruitless is an important gene involved mostly in several aspects of male courtship behavior, the few studies so far have explained its high rates of evolution by relaxed selective constraints. This would indicate that a large portion of this gene has evolved neutrally, contrary to what has been observed for other genes in the sex cascade. 相似文献15.
Radim Cegan Gabriel AB Marais Hana Kubekova Nicolas Blavet Alex Widmer Boris Vyskot Jaroslav Doležel Jan Šafář Roman Hobza 《BMC plant biology》2010,10(1):180
Background
The evolution of sex chromosomes is often accompanied by gene or chromosome rearrangements. Recently, the gene AP3 was characterized in the dioecious plant species Silene latifolia. It was suggested that this gene had been transferred from an autosome to the Y chromosome. 相似文献16.
Nafiu Amidu William KBA Owiredu Eric Woode Otchere Addai-Mensah Lawrence Quaye Abass Alhassan Edmond A Tagoe 《Reproductive biology and endocrinology : RB&E》2010,8(1):106
Background
Sexuality is a complex phenomenon that is being influenced by psychological as well as physiological factors. Its dysfunction includes desire, arousal, orgasmic and sex pain disorders. The present study aimed to assess the incidence of sexual dysfunction (SD) and related risk factors in a cohort of Ghanaian women. 相似文献17.
Rute ST Martins Laurence AM Deloffre Constantinos C Mylonas Deborah M Power Adelino VM Canário 《Reproductive biology and endocrinology : RB&E》2007,5(1):19
Background
DAX1 (NR0B1), a member of the nuclear receptors super family, has been shown to be involved in the genetic sex determination and in gonadal differentiation in several vertebrate species. In the aquaculture fish European sea bass, Dicentrarchus labrax, and in the generality of fish species, the mechanisms of sex determination and differentiation have not been elucidated. The present study aimed at characterizing the European DAX1 gene and its developmental expression at the mRNA level. 相似文献18.
Background
SRY is the pivotal gene initiating male sex determination in most mammals, but how its expression is regulated is still not understood. In this study we derived novel SRY 5' flanking genomic sequence data from bovine and caprine genomic BAC clones. 相似文献19.
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Hans Ellegren Lina Hultin-Rosenberg Björn Brunström Lennart Dencker Kim Kultima Birger Scholz 《BMC biology》2007,5(1):40-12