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1.
J G Vandenbergh 《Journal of animal science》1989,67(7):1841-1847
Social cues, often in the form of priming pheromones, can retard or enhance the rate of sexual development in a variety of mammals. The complex interactions between the social environment and reproduction have been explored most thoroughly in the house mouse. A urinary pheromone produced by females in a group inhibits sexual development, and a urinary pheromone from adult males accelerates onset of puberty in juvenile females. These priming pheromones apparently are detected by the vomeronasal organ and induce the changes in ovarian function via changes in the hypothalamic-pituitary system. Accelerated onset of puberty is not accompanied by deficits in reproductive performance. Puberty acceleration can have important management implications for domestic farm animals. It already is proving useful for manipulation in rearing swine and in synchronizing seasonal reproductive recrudescence in sheep. In cattle, the results are less clear that signals from the bull can hasten onset of puberty in heifers. The effect may be operable only under certain nutritional or other interacting conditions. Presumably, the postpartum anestrus period in the cow can be shortened by stimulation from the bull, although pheromones have not been implicated in this effect. 相似文献
2.
为了研究新型公猪信息素对大龄后备母猪发情的影响,选取526头255日龄左右无初情期记录的二元回交后备母猪,随机分为2组,试验组每天在鼻镜上喷新型公猪信息素4 mL,连喷21 d,21 d后还不发情的猪则并栏7 d应激,每天喷1次新型公猪信息素,每次4 mL;期间有发情表现的猪即可停止喷洒。对照组在相同条件下仅仅依靠人工查情,期间只要出现发情并且符合配种条件即可配种。分别统计每组的发情率,刺激-发情间隔。结果发现,在无初情期记录的大龄后备母猪.上每天喷4 mL新型公猪信息素,可显著提升后备母猪的发情比例(P<0.01),缩短刺激-发情的间隔(P<0.01)。由此得出,对大龄后备母猪使用新型公猪信息素28 d,可有效提升其发情率,缩短刺激-发情间隔。 相似文献
3.
外激素是生物体向环境释放的一种或多种化学物质的混合物,在环境中起着同种个体间传递信息、引起对方产生特殊反应的一类生物活性物质。在动物中,外激素是应用最广和最古老的通信方式,它们表现的是一种精练过的社会行为和繁殖策略的工具。对外激素在化学特性、产生器官、接受器官、作用及其作用途径方面取得的研究进展作一概述,以亟为该领域的研究提供参考。 相似文献
4.
水分胁迫下雌雄异株植物草繁殖策略的可塑性调节 总被引：1，自引：0，他引：1
研究雌雄异株草本植物应对环境胁迫的繁殖策略及生殖分配可塑性,对发展雌雄异株植物的生活史进化理论和该类植物资源保护利用具有重要意义。实验以草为材料,通过设置轻度（LS）、中度（MS）、重度（RS）水分胁迫梯度,研究雌、雄单株的花芽分化、生物量分配、花穗性状、花药（或子房）数、花粉数及活力等与生殖生长相关的可塑性。结果表明：1）草通过提前花芽分化应对水分胁迫,雄株先于雌株进入生殖生长（P ＜0．01）。2）雄株增加生殖分配应对 LS 胁迫,雌株减少花穗生物量应对水分胁迫;在 RS 胁迫时雄株的生殖分配为雌株的近3倍。3）草通过减少花穗数应对胁迫,雄株显著增加单个花穗的小花数来应对轻中度缺水（P ＜0．05）,雌株则减少开花频次降低水分胁迫下生殖能量消耗。4）轻中度水分胁迫对雌株子房宽度无显著影响;中重度胁迫虽使雄株显著缩短了花药长度、减少了单个花药的花粉数（P ＜0．05）,但花粉大小、花粉活性受影响较小。5）雄株花穗的 POD 和 SOD活性显著高于雌株,雄株对水分胁迫更加敏感。在水分胁迫下,草在生存和防御功能稳定的基础上,可以通过协调分配有限资源,实现有性繁殖来完成草本植物较为短暂的生活史。 相似文献
5.
Reproductive Performance of Native Pulawska and High Productivity Polish Landrace Sows in the Context of Stress During the Period of Early Pregnancy 
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下载免费PDF全文 M Babicz M Szyndler‐Nędza E Skrzypczak A Kasprzyk 《Reproduction in domestic animals》2016,51(1):91-97
Experiments revealed that it is necessary to get rid of genotypes RYR1C/T and RYR1T/T because of problems with meat quality and reproduction of gilts and sows. This phenomenon, however, is of individual nature and is characterized by high variability. The aim of the study was to analyse the influence of stressogenic factors in native Pu?awska and high productivity Polish Landrace breed sows during the period of low pregnancy on reproductive performance and maternal behaviour. Sows in the 2nd reproduction cycle were assigned into groups of five animals as follows: control (C) of RYR1 C/C genotype and experimental (E) of RYR1 C/T genotype. In all, 30 Pu?awska breed sows and 30 PL breed sows were analysed. During the early stage of pregnancy (days 42–84), experimental groups were subjected to the action of stressogenic factors: elevated temperature, noisy and rough treatment of sows by service personnel and immobilization stress. The effect of stressogenic factors was referred to the reproductive performance of sows. Pu?awska and PL breed sows from the experimental groups were subjected to the evaluation of maternal traits on the basis of perinatal behaviour determined with the help of an ethogram. Analysis of the results of reproduction and the behaviour of the sows confirmed the higher resistance to stressogenic factors of the Pu?awska breed. The performed analysis of reproduction and behaviour confirmed that heterozygotic genotypes in the RYR1 locus exhibited less advantageous reproduction, which corroborates the hypothesis about a negative impact of the T allele on swine productivity. 相似文献
6.
《African Zoology》2013,48(3):259-262
This paper provides evidence for the extralimital establishment and spread of Pseudocrenilabrus philander in the Baakens River, Eastern Cape, South Africa. Since the first occurrence record at a single locality in 1994 this species has now spread throughout the river and the population contains both reproductive adults and juveniles. Gut content analysis demonstrated potential dietary overlap with native fishes and predation on fish larvae. Pseudocrenilabrus philander in the Baakens River therefore satisfies all criteria for an invasive species in this river and was categorised as invasive using a unified framework for biological invasions. 相似文献
7.
TG McEvoy 《Reproduction in domestic animals》2003,38(4):268-275
Assisted reproductive technologies, as applied to domestic animals, can exert both novel and wide‐ranging influences on the development, viability and welfare of offspring. Some of the changes are evident immediately or soon after the time at which a manipulative procedure is carried out, while other changes may not be evident until later in development or, perhaps, may remain undetected throughout an animal's lifetime. The present review explores some of the consequences – in terms of foetal, placental, neonatal and post‐natal effects – of exposing embryos of cattle, sheep and other species to in vitro culture per se or, during culture, to physically invasive technologies including gene injection and nuclear transfer. The innate sensitivity of oocytes and recently fertilized eggs to their in vitro environment is illustrated by an examination of the later developmental repercussions resulting from apparently innocuous choices related to in vitro culture medium formulations. In contrast, an inherent resilience and paradoxical readiness to resume development following the traumas of nuclear transfer procedures is also in evidence. The extent to which assisted reproductive technologies will succeed, where relevant, in the domestic animal sector will be influenced by our appreciation of embryo requirements, for both short‐ and long‐term developmental fitness, during their earliest developmental stages. Evidence of species‐specific needs is testimony to the challenges ahead. Ultimately, our ability and inclination to resolve the limitations associated with current procedures will probably be greatly enhanced if predictive indicators (genetic, epigenetic or functional markers) of later developmental fitness can be identified. 相似文献
8.
Understanding life history patterns, individual fitness and population fitness can assist with conservation of endangered species. Field data on life history traits (i.e. age specific fecundity, age specific mortality, age at first reproduction, litter size and adult life expectancy) were collected from 121 Hainan Eld's deer (Cervus eldi hainanus Thomas, 1918), an in situ herd of an endemic, rare and endangered cervid inhabiting Bangxi Natural Reserve of Hainan Island, from 1990 to 2002. First, we constructed a dynamic life table to analyze the life history pattern of the population, which showed that the difference between the average lifespan of males and females was not significant (P > 0.05), and that the difference between the average lifespan of the whole Hainan Eld's deer population and that of other Eld's deer populations living in South Asia (P > 0.05), North America (P > 0.05) and Europe (P > 0.05) was not significant. Second, we used individual reproductive success or number of offspring of a male over its lifetime to estimate male individual fitness. Statistic analysis showed that male individual fitness was not significantly correlated with total antler velvet mass. Third, we used the population intrinsic rate of increase to measure population fitness, and population fitness of Hainan Eld's deer was compared with similar indexes of 5 other cervid species. Hainan Eld's deer population fitness index was 0.012, the second lowest value relative to other cervids. Results indicated that this rare species is still endangered and is in need of additional protection. 相似文献
9.
Most studies support the viewpoint that the vomeronasal organ has a profound effect on conspecific odor recognition, scent marking and mating behavior in the golden hamster (Mesocricetus auratus). However, the role of the vomeronasal organ in social odor recognition, social interaction and fitness is not well understood. Therefore, we conducted a series of behavioral and physiological tests to examine the referred points in golden hamster. We found that male hamsters with vomeronasal organ lesion showed no preference between a predator odor (the anal gland secretion of the Siberian weasels (Mustela sibirica) and putative female pheromone components (myristic acid and palmitic acid), but were still able to discriminate between these 2 kinds of odors. In behavioral tests of anxiety, we found that vomeronasal organ removal causes female hamsters to spend much less time in center grids and to cross fewer center grids and males to make fewer crossings between light and dark boxes than sham‐operated controls. This indicates that a chronic vomeronasal organ lesion induced anxious responses in females. In aggressive behavioral tests, we found that a chronic vomeronasal organ lesion decreased agonistic behavior in female hamsters but not in males. The pup growth and litter size show no differences between the 2 groups. All together, our data suggested that vomeronasal organ ablation disrupted the olfactory recognition of social chemosignals in males, and induced anxiety‐like and aggressive behavior changes in females. However, a vomeronasal organ lesion did not affect the reproductive capacity and fitness of hamsters. Our studies may have important implications concerning the role of the vomeronasal organ in golden hamsters and also in rodents. 相似文献
10.
Effect of a Pheromone on Stress‐Associated Reactivation of Feline Herpesvirus‐1 in Experimentally Inoculated Kittens 下载免费PDF全文
下载免费PDF全文 Elena T. Contreras E. Hodgkins V. Tynes A. Beck F. Olea‐Popelka M.R. Lappin 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2018,32(1):406-417
Background
Stress contributes to reactivation of feline herpesvirus‐1 (FHV‐1). The usage of pheromones to decrease stress in FHV‐1 experimentally inoculated kittens has not previously been investigated.Hypothesis/Objectives
To determine whether a feline pheromone would lessen stress, resulting in decreased recurrence of FHV‐1‐associated illness in kittens.Animals
Twelve 5‐month‐old, purpose‐bred kittens.Methods
Randomized, double‐blind, placebo‐controlled clinical trial. Kittens previously infected with the same dose of FHV‐1 were randomized into 2 separate but identical group rooms. After a 2‐week equilibration period, a diffuser containing either the pheromone or placebo was placed in each of the rooms, and the kittens acclimated for an additional 2 weeks. Every 2 weeks thereafter, for the 8‐week study period, housing was alternated between kennel‐ and group housing. Blinded observers applied a standardized clinical and behavioral scoring rubric daily. After each 2‐week period, serum cortisol concentrations and quantitative PCR for FHV‐1 and glyceraldehyde 3‐phosphate dehydrogenase (GAPDH) ratios were evaluated. Clinical, behavioral, and laboratory test results were compared between groups within individual and combined study periods.Results
Sneezing occurred more frequently in the placebo group during individual (P = 0.006) and combined study periods (P = 0.001). Sleep at the end of observation periods occurred more frequently in the pheromone group during individual (P = 0.006) and combined study periods (P < 0.001).Conclusions and Clinical Importance
The findings suggest that the pheromone decreased stress, and the decrease in stress response may have resulted in decreased sneezing associated with FHV‐1. 相似文献11.
从诱情公猪看信息素的作用 总被引：1，自引：1，他引：0
越来越多的养猪场开始重视公猪信息素,在降低使用诱情公猪的生物安全风险和提高育种效率方面的作用。文章将通过回顾一系列的试验数据,包括不同性欲和年龄的公猪诱情效果上的差别,唾液腺手术后的公猪对母猪诱情的影响,以及不同的信息素产品在诱导母猪性行为以及体内激素水平的表达上的区别,来说明唾液类似物是公猪天然信息素的主要载体。不同的公猪的诱情效果差别,主要是源于唾液类似物中信息素的浓度以及分泌量的差别。通过分析雄烯酮对母猪性行为以及体内激素水平的影响,发现公猪分泌的信息素可能是多种分子的混合物,而不是单分子组成,不同性质的信息素将产生不同效应。 相似文献
12.
Lúcia PEREIRA Ana VASQUES Paula MAIA Maria Joo RAMOS PEREIRA Carlos FONSECA Milena MATOS 《Integrative zoology》2019,14(3):280-292
The stone marten (Martes foina) is a carnivorous mammal that often consumes fleshy fruits, thus potentially promoting seed dispersion. The present study was developed in Bussaco National Forest, central Portugal, and aimed to assess the potential role of the stone marten in dispersing native and exotic plants in different forest landscape types. Seeds from stone marten scats and fleshy fruits were collected monthly and were thereafter identified and sowed in a nursery, following a randomized experimental setup. Plant emergence was monitored fortnightly. Generalized linear models were used to test for differences in time and success of emergence between seeds from scats and fruits of 3 native species (Rubus ulmifolius, Arbutus unedo and Celtis australis) and 1 exotic plant species with invasive behavior (Prunus laurocerasus). Fruit consumption by the stone martens significantly increased and accelerated the germination of the native R. ulmifolius but had no effect on the other 2 native species or on the invasive species. This suggested that stone martens contribute to gene flow and forest regeneration by dispersing native plant seeds. However, although the germination was not enhanced in the invasive species, the preference of stone martens for these fruits may potentially contribute to the proliferation of P. laurocerasus. Our study represents a contribution to better understanding the fauna and flora interactions, enabling for a more conscious and effective decision‐making in forest management. 相似文献
13.
Weiguo DU Travis R. ROBBINS Daniel A. WARNER Tracy LANGKILDE Richard SHINE 《Integrative zoology》2014,9(3):360-371
Geographic variation in life‐history traits among populations of wide‐ranging species is influenced by both spatial and temporal aspects of the environment. Rarely, however, are the effects of both aspects examined concurrently. We collected gravid female lizards (Sceloporus undulatus) from northern (Indiana), central (Mississippi) and southern (Florida) populations, spanning nearly the full latitudinal range of the species, to examine amongpopulation differences in strategies of reproductive energy allocation. Adult females from the southern population were smaller, and produced fewer and smaller eggs in their first clutches than did females from the more northern populations. Southern females were more likely to produce a second clutch, and second clutches were smaller than first clutches for females from the 2 northern populations. Together these trends eliminated population differences in overall reproductive output after accounting for body size. The trend for greater reproductive energy to be allocated to first clutches at higher latitudes, and to later clutches at lower latitudes is corroborated by published data from field studies on multiple populations. Distributing reproductive effort by producing more clutches of smaller eggs may be an adaptive response to the long season available for egg incubation and lizard activity in sub‐tropical southern environments. In contrast, allocating greater resources to early reproduction may enhance maternal fitness in the relatively short activity seasons that characterize more northern sites. 相似文献
14.
根茎冰草是多年生短根茎丛生禾草,具有较高的饲用价值。本研究采取大样本取样,对松嫩平原人工建植下根茎冰草二年生同生群无性系的生长与生产的可塑性和规律性进行了定量分析,结果表明：根茎冰草同生群无性系丛径的变异系数为31.7%,生殖株和营养株数量的变异系数分别为78.5%和63.0%,生物量变异系数分别为89.8%和64.3%;根茎长和种子千粒重的变异系数分别为111.4%和8.4%。各构件数量特征均存在不同程度的可塑性,其中,生产特征的可塑性高于生长,构件数量特征的可塑性均以生殖株高于营养株,潜在无性系高于现实无性系;生殖构件生长与分配的数量性状高于种子质量性状。根茎冰草无性系的调节功能主要体现在：无性系大小及构件生长与生产的可塑性均较严格地遵循异速或同速生长规律;生殖分配与营养生长之间存在权衡。 相似文献
15.
Gregor Yeates Sten-olof Dimander Peter Waller Johan Höglund 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(4):197-206
The size and composition of the nematode assemblage in soil under faecal pats derived from young cattle treated or untreated with either ivermectin sustained-release boluses, or the nematophagous fungus Duddingtonia flagrans, were studied in each of three years. Soil samples taken 4, 6, 8 and 10 weeks after four deposition dates in 1998 showed significant temporal effects in many taxa and treatment effects in a few genera. In 2000, soil samples taken 10 weeks after deposition in July, August and September showed treatment effects in the plant-associated Tylenchus and Cephalenchus, and the bacterial-feeding Cephalobus 1 and Cephalobus 2 taxa. However, overall it was found that the nematode assemblages were similar below all three types of pat, and the assemblages varied with the season of deposition. D. flagrans, the novel biological control agent being tested against the free-living stages of nematode parasites of cattle, had no detectable impact on the size or the structure of the soil nematode communities under the faecal pats. 相似文献
16.
Zhixiu Wang Laidi Wang Yang Zhang Ying Yao Wenming Zhao Qi Xu Guohong Chen 《Journal of animal physiology and animal nutrition》2021,105(5):938-945
Zhedong white goose (Anser cygnoides domesticus) is a native Chinese breed with strong broodiness and low egg production, which is related to the physiology of reproduction. However, thus far, the physiology of goose reproduction has not been well elucidated. In the present study, the ovarian morphology and reproductive hormones of Zhedong white geese were investigated during the reproductive cycle (the laying and brooding periods). The results showed that the surface of the ovary was atrophied and follicular atresia appeared to some extent in the brooding period compared with the laying period. The concentrations of follicle-stimulating hormone, progesterone and luteinizing hormone were significantly higher than those in the brooding period (p < 0.05). In contrast, the concentrations of prolactin (PRL) and anti-Müllerian hormone (AMH) in the laying period were significantly lower than those in the brooding period (p < 0.05). In addition, the mRNA expression levels of PRL, AMH, dopamine-β-hydroxylase (DβH) and cytochrome P450 side-chain cleavage enzyme (P450scc) were detected in the hypothalamus, pituitary and ovaries by using real-time polymerase chain reaction. The results showed that AMH mRNA was expressed specifically in ovary tissue. The expression levels of DβH and PRL in the brooding period was significantly higher than those in the laying period in the three tissues, especially in the early and middle stages of the brooding period. Moreover, AMH mRNA expression in the ovaries presented the same trend. In addition, P450scc mRNA was highly expressed in both the ovary and pituitary in the laying period. These results revealed the remarkable features of ovarian morphology and characterized the hormonal pattern and expression profile during the reproductive cycle, all of which contribute to understanding the differences in reproductive physiology between the laying and brooding periods in Zhedong white geese. 相似文献
17.
A. Vazirzadeh B. Mojazi Amiri A. Fostier 《Journal of animal physiology and animal nutrition》2014,98(6):1060-1067
Wild common carp (Cyprinus carpio carpio) is a native valuable but threatened species from the south‐eastern Caspian Sea in which the endocrine control of its reproduction has not been studied. The objectives of this research were to study the reproductive strategy and changes in steroid hormones during ovarian development. From October 2009 to June 2010, 65 adult females were caught from the Golestan coast (Iran) and the ovarian histology, and gonadosomatic and hepatosomatic indices (GSI and HSI) were studied. Also, the plasma profiles of steroid hormones including testosterone (T), 17β‐estradiol (E2) and 17α‐, 20β‐dihydroxyprogesterone (DHP) were measured by radioimmunoassay. The GSI increased gradually during sampling times and reached maximum value at the peak of reproduction season, but the HSI decreased during spawning season. All stages of ovarian development, except the stage of Balbiani bodies, were recorded macro‐ and microscopically. Spent fish were caught at six of nine sampling times. The peaks of spawning were at late winter and early spring. The results of this study showed that the majority of wild carp collected during the sampling period displayed asynchronous oocyte development. Plasma T showed no significant differences during sampling times or at different stages of ovarian development. The level of E2 decreased gradually during sampling times reached minimum value at the spawning season, and highest value was recorded at tertiary vitellogenesis stage. The plasma levels of DHP during late winter and early spring were significantly higher than those of other sampling periods and its maximum level associated with oocyte maturation stage. 相似文献
18.
Kazuya KOBAYASHI Sachiko ARIOKA Motonori HOSHI Midori MATSUMOTO 《Integrative zoology》2009,4(3):265-271
Certain freshwater planarians reproduce asexually as well as sexually, and their chromosomal ploidies include polyploidy, aneuploidy and mixoploidy. Previously, we successfully performed an experiment in which a clonal population produced by asexual reproduction of the Dugesia ryukyuensis (OH strain) switched to the sexual mode of reproduction. Worms of this strain are triploid with a pericentric inversion on Chromosome 4. The worms were switched to sexual reproduction after being fed with sexually mature Bdellocephala brunnea, which is a sexually reproducing species. The resulting sexualized OH strain produced cocoons filled with several eggs. Two putative factors, Mendelian factor(s) and chromosomal control(s), have been proposed as determining the reproductive mode. The present study demonstrated that inbreeding of the resultant sexualized worms produced the following four types of offspring through sexual reproduction: diploid asexual worms, triploid asexual worms, diploid sexual worms and triploid sexual worms. The chromosomal mutation on Chromosome 4 was inherited by these offspring independent of their reproductive mode. These results provide two important pieces of information: (i) the putative genetic factor was not necessarily inherited in a Mendelian fashion; and (ii) the reproductive mode is not regulated by chromosomal changes such as polyploidy or chromosomal mutations. This suggests that asexuality in D. ryukyuensis is regulated by an unknown factor(s) other than a Mendelian factor or a chromosomal control. 相似文献
19.
Shannon A. RICHARD Eric A. TILLMAN John S. HUMPHREY Michael L. AVERY M. Rockwell PARKER 《Integrative zoology》2019,14(5):460-469
Animals communicate with potential mates using species‐specific signals, and pheromones are powerful sexual signals that modify conspecific behavior to facilitate mate location. Among the vertebrates, snakes are especially adept in mate searching via chemical trailing, which is particularly relevant given that many snake species are invasive outside their native ranges. Chemical signals used in mate choice are, thus, potentially valuable tools for management of invasive snake species. The Burmese python (Python bivittatus) is an invasive snake in the Florida Everglades where it is negatively impacting native fauna. In this study, we sought to: (i) determine if males can follow conspecific chemical trails in a Y‐maze; and (ii) describe the mate searching behaviors exhibited by males while trailing. All males consistently followed a single female scent trail in the maze, but when only a male scent trail was present they did not discriminate between the male and blank arms. Rate of tongue‐flicking, a proxy for chemosensory sampling, was also marginally higher when males were following female versus male scent trails. However, when both female and male scent trails were simultaneously present in the Y‐maze, males did not show a preference for the female arm, although the tongue‐flick rate was higher in the female‐only trial compared to female versus male. Analyses of multiple male behaviors individually and using an ethogram revealed that behaviors were more frequent and complex in the female‐only trials compared to male‐only trials. Additional behavioral trials are needed to determine if an effective pheromonal approach to Burmese python management is possible. 相似文献
20.
Xiaoyun He Zhuangbiao Zhang Qiuyue Liu Mingxing Chu 《Reproduction in domestic animals》2019,54(10):1400-1410
Previous researches have shown that MTNR1A plays an essential role in sheep reproduction. However, most researches focused more on the reproductive seasonality of sheep, and few scientists had studied the association of polymorphisms of the MTNR1A gene with ovine litter size and reproductive seasonality. Therefore, we chose MTNR1A gene to detect its novel sequence polymorphisms and population genetics and analyse their association with seasonal reproduction and litter size in ewes. The mRNA expression level in hypothalamus, pituitary and ovary was also detected. In this study, five polymorphisms (g.15118664G > T, g.15118683C > T, g.15118756C > T, g.15118774C > T and g.15118951G > A) were identified in exon 2. Most importantly, the g.15118683C > T and g.15118951G > A were significant difference between year‐round oestrous sheep and seasonal oestrous sheep (p < .01), and g.15118756C > T had a great effect on litter size of Small Tail Han sheep (p < .05). In addition, the mRNA expression level of MTNR1A in the hypothalamus of polytocous Small Tail Han sheep was significantly higher than that in monotocous Small Tail Han sheep (p < .01) and the expression of MTNR1A in the hypothalamus of year‐round oestrous sheep was significantly higher than that in seasonal oestrous sheep (p < .01). Polymorphisms in exon 2 may regulate the reproductive seasonality and litter size of ewes by influencing gene expression to regulate the reproductive seasonality and litter size of ewes. Our studies provided useful guidance in marker‐assisted selection of the litter size in Small Tail Han sheep. 相似文献