Association of PRLR,IGF1, and LEP genes polymorphism with milk production and litter size in Egyptian Zaraibi goat

Tropical Animal Health and Production - The co-administration of commercial live fowlpox (FP) and Newcastle disease (ND) vaccines when given by non-invasive (needle-free) routes was demonstrated to...     

A new HpaII PCR-RFLP within the porcine prolactin receptor (PRLR) gene and study of its effect on litter size and number of teats

DNA polymorphism of the porcine prolactin receptor gene ( PRLR ) was investigated and used to study its effect on litter size and number of teats in pigs. By means of PRLR gene sequence homology in pig, human and other species, primers were designed for PCR amplification within 5' unknown (to date) part of the prolactin receptor gene in pigs. In this part of the gene, a new polymorphism with Hpa II restriction endonuclease was detected. Alu I polymorphism described before and our new Hpa II polymorphism were used to study the associations with reproduction traits. The PCR restriction fragment length polymorphism (PCR-RFLP) method was used to genotype Alu I and Hpa II loci of the PRLR gene in line A with 83 sows of Landrace breed and in two lines (B and C) with 75 and 86 Large White sows, respectively. Statistical analysis of 1020 litters showed that Alu I locus was associated with litter size mainly in Landrace and affected the first parities, while Hpa II locus of the gene was associated with the same traits in Landrace and Large White pigs and mainly affected numbers of weaned of pigs. The magnitude of the effect varied by population with the effects exceeding two pigs per litter in Landrace line and 1 pig per litter in Large White populations.     

Effects of prolactin receptor genotype on the litter size of Mangalica

The aim of this study was to detect different alleles of the prolactin receptor (PRLR) gene and to examine their effects on the litter size of the indigenous Hungarian pig, the Mangalica. G1789A single nucleotide polymorphism (SNP) was investigated as a candidate for litter size. Samples from 80 purebred Mangalica sows and data of their 335 litters were provided by Olmos & Tóth Ltd. Hair follicles were used to isolate the required DNA. Allelic discrimination was performed by means of the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method using the AluI restriction enzyme and agarose gel electrophoresis. In the population examined, the A allele was found to be preferable in the Mangalica breed group. The most advantageous AA genotype was the least prevalent (8.75%), while the frequencies of AB and BB were 40% and 51.25%, respectively. Remarkably, the average number of piglets born alive per litter was 1.11 ± 0.39 higher in sows with AA as compared to those with BB genotype. By raising the frequency of the AA genotype, the litter size is likely to increase. However, the effect of PRLR genotypes can differ among pig breeds and even lines. Further studies may be required to observe and estimate possible pleiotropic effects of this polymorphism on other traits.     

Expression of genes involved in progesterone receptor paracrine signaling and their effect on litter size in pigs

Background: Embryonic mortality during the period of implantation strongly affects litter size in pigs. Progesterone receptor(PGR) paracrine signaling has been recognized to play a significant role in embryonic implantation. IHH,NR2F2, BMP2, FKBP4 and HAND2 were proved to involve in PGR paracrine signaling. The objective of this study was to evaluate the expression of IHH, NR2F2, BMP2, FKBP4 and HAND2 in endometrium of pregnant sows and to further investigate these genes' effect on litter size in pigs. Real-time PCR, western blot and immunostaining were used to study target genes/proteins expression in endometrium in pigs. RFLP-PCR was used to detect single nucleotide polymorphisms(SNPs) of target genes.Results: The results showed that the m RNA and protein expression levels of IHH, NR2F2 and BMP2 were up-regulated during implantation period(P 0.05 or P 0.01). All target proteins were mainly observed in luminal epithelium and glandular epithelium. Interestingly, the staining of NR2F2 and HAND2 was also strong in stroma. SNPs detection revealed that there was a-204 C A mutation in promoter region of NR2F2 gene. Three genotypes were found in Large White, Landrace and Duroc sows. A total of 1847 litter records from 625 sows genotyped at NR2F2 gene were used to analyze the total number born(TNB) and number born alive(NBA). The study of the effect on litter size suggested that sows with genotype CC tend to have higher litter size.Conclusions: These results showed the expression patterns of genes/proteins involved in PGR paracrine signaling over implantation time. And the candidate gene for litter size was identified from genes involved in this signaling. This study could be a resource for further studies to identify the roles of these genes for embryonic implantation in pigs.     

骨形成蛋白15基因Bcu I多态性对猪产仔性能的影响

采用PCR—RFLP方法,检测了小梅山猪和大白猪骨形成蛋白15（BMP15）基因exon2的多态性,结果显示,在这2个品种中均有A和B两个等位基因存在。利用最小二乘分析研究了该多态位点对猪头胎、二胎和经产的总产仔数和产活仔数的影响。结果表明,在小梅山猪中,不同基因型经产母猪的总产仔数和产活仔数间差异显著,AA产活仔数最高,为14．28头,BB总产仔数和产活仔数最低,分别为12．67头和12．33头;大白猪中,不同基因型母猪在头胎总产仔数和经产总产仔数方面差异显著,其他方面差异均不显著,但都呈现出AA〉AB〉BB的趋势。     

Oestrogen receptor genotypes and litter size in Hungarian Large White pigs

A total of 869 litter records of 226 Hungarian Large White sows have been analysed to investigate the possible use of the oestrogen receptor gene (ESR) as marker to improve litter size. First, second and later parities have been evaluated separately. Frequencies of A = 0.55 and B =0.45 have been calculated for the two ESR alleles and the observed/expected number of the three genotypes were as follows: AA: 71/69.1, AB: 108/111.8 and BB: 47/45.1. BB type first and later parity sows were superior to AB and AA sows for number born alive (NBA), total number of born (TNB) and the corrected number of weaned piglets (CNW), respectively.     

大白猪产仔数相关基因多态性及其遗传效应

为比较繁殖性状主效基因对不同品系大白猪产仔性能的影响,以便在不同品系大白猪选种实际应用提供依据,本试验采用PCR-RFLP技术,分别对促卵泡素亚基β(FSHβ)、催乳素受体(PRLR)、视黄醛结合蛋白(RBP4)、核受体辅激活蛋白Ⅰ(NCOA1)、瘦素(LEP)等5种与繁殖性状相关候选基因的基因型频率以及不同基因型的总产仔数和产活仔数在英系、美系大白猪群体中进行了检测与关联分析。结果显示:NCOA1和LEP基因多态位点分别在英系和美系大白猪中未检测到BB基因型,其他基因多态位点均存在AA、AB、BB等3种基因型,在美系大白猪群体中5个基因多态位点均符合Hardy-Weinberg平衡定律(P>0.05);而在英系大白猪群体中除在FSHβ、NCOA1、LEP基因多态位点均处于Hardy-Weinberg平衡状态(P>0.05)外,在PRLR、RBP4基因多态位点处于Hardy-Weinberg不平衡状态(P<0.01)。各基因不同基因型与产仔性状关联分析结果表明,无论是英系大白猪还是美系大白猪,FSHβ基因多态位点在窝总产仔数和产活仔数中均表现为BB型为有利基因型,在美系大白猪中BB型较AA型总产仔数高1.6961头(P<0.05),产活仔数高1.696 9头(P<0.05),但在英系大白猪中不存在显著差异(P>0.05);LEP基因在英系大白猪中BB型为有利基因型,分别较AA型母猪总产仔数高0.790 7头、产活仔数高1.409 3头(P<0.05),而在美系大白猪中不存在显著差异(P>0.05);PRLR、RBP4、NCOA1基因对产仔数不存在显著差异(P>0.05)。     

Genetic structure of candidate genes for litter size in Italian Large White pigs

The aim of this work was to verify whether polymorphisms in candidate genes for litter size segregate in Italian Large White (ITLW) pigs. We genotyped 120 sows that belonged to six different farms for 10 single nucleotide polymorphisms (SNPs) of 10 different genes. Polymorphisms in the chosen genes had already been associated with litter-size traits in other pig populations and were candidates for function and/or chromosomal location. The results indicated that the CLGN, pDAZL, and RFN4 SNPs were not segregating in the genotyped samples. The remaining seven markers were polymorphic with minor allele frequencies ranging from 0.10 (AFP) to 0.48 (RBP4). Because of the observed genetic variabilities in the investigated loci, the polymorphisms in the AFP, BMPR1B, CXCL10, ESR2, GNRHR, MAN2B2, and RBP4 genes can be considered suitable markers for association studies with litter-size traits in ITLW pigs.

     

Plasma leptin levels in pigs with different leptin and leptin receptor genotypes

A C3469T mutation at exon 3 of the pig leptin (Lep) gene has been genotyped in diverse pig breeds yielding controversial results with regard to its association with growth, fatness and carcass traits. A similar situation has been reported for a HpaII restriction fragment length polymorphism (RFLP) in the pig leptin receptor (Lepr) gene, where associations were found depending on the statistical model employed. The main objective of our work was to investigate if leptin plasma concentrations differ in pigs with different C3469T and Lepr HpaII RFLP genotypes. With this aim, we have measured plasma leptin levels at 160 days in 68 Landrace pigs with different Lep C3469T and Lepr HpaII RFLP genotypes. Neither Lep (TT: 11.68 ng/ml, TC: 10.71 ng/ml) nor Lepr (AA: 12.6 ng/ml, AB: 10.93 ng/ml, BB: 11.74 ng/ml) genotypes influenced significantly plasma Lep concentration. Moreover, we did not find any association between Lep and Lepr genotypes and phenotypic variation at growth and fatness traits in a commercial population of 320 Landrace pigs.     

DNA polymorphism of 5' flanking region of prolactin gene and its association with litter size in sheep

A single nucleotide polymorphism of 5' flanking region of the prolactin gene was investigated in both high prolificacy breeds (Small Tail Han and Hu sheep) and low prolificacy breeds (Dorset and Suffolk sheep) using polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP). The results indicated that two genotypes (AA and AB) were detected in Small Tail Han sheep (n   =   239), only one genotype (AA) was detected in Hu (n   =   40), Dorset (n   =   50) and Suffolk sheep (n   =   39). The mutant homozygous genotype (BB) was not detected in four sheep breeds. In Small Tail Han sheep (n   =   239), the frequency of genotypes AA and AB was 0.91 and 0.09, the frequency of the A and B alleles was 0.95 and 0.05, respectively. The fitness tests showed that the Small Tail Han sheep population was in Hardy–Weinberg equilibrium. Sequencing revealed a mutation (G→T) at the position 63 bp of the 5' flanking region of prolactin gene in AB genotype compared with AA genotype in Small Tail Han sheep. The Small Tail Han ewes with AB genotype had 0.83 (p < 0.05) lambs more than those with AA genotype. These results preliminarily showed that the prolactin locus is either a major gene that influences the high prolificacy in Small Tail Han sheep or is in close linkage with such a gene.     

猪GPX5,FUT1和PRLR基因的遗传多态性及遗传效应分析

为了分析谷胱甘肽过氧化物酶5基因(Glutathion Peroxidase 5,GPX5),岩藻糖转移酶1基因(α1-Fucosytransferase,FUT1)和催乳素受体基因(Prolactin receptor,PRLR)在野猪与大白猪杂交的F1代群体中的遗传多态性及遗传效应。采用PCR-RFLP方法检测了GPX5,FUT1和PRLR基因的多态性,分析其对初生重(LiB)和30日龄体重(Li30)的遗传效应。结果表明,除了PRLR基因外,其余2个基因的基因频率与大白猪已有研究结果基本一致;PRLR基因的AA型个体在Li30上比AB和BB型个体可显著增重1.42～1.47 kg(P0.05);GPX5和FUT1基因对这2个性状的效应均不显著。结果提示,野猪血统的引入没有显著改变现有猪群的遗传基础,PRLR基因可在生产中考虑应用。     

Genetic determination of individual birth weight, litter weight and litter size in Mukota pigs

Genetic parameters for individual birth weight (IBWT), total number of pigs born (NBT), number of pigs born alive (NBA), number of pigs born dead (NBD) and litter weight at birth (LBWT) were estimated using 1961 Mukota pigs kept at the University of Zimbabwe Farm, Harare, Zimbabwe. Variance components were estimated for IBWT based on a direct-maternal genetic effects model. The genetic relationships among NBT, NBA, NBD and LBWT were assessed using a multi-trait direct effects model. For LBWT, the direct, maternal and common environmental litter proportions on the phenotypic variance were 0.090, 0.033 and 0.009, respectively. After adjustment of IBWT for NBA, phenotypic fractions were 0.091, 0.034 and 0.011 for direct, maternal and litter effects. The correlation between the direct and maternal genetic effects of IBWT was − 0.354 and − 0.295, with and without adjustment for NBT. Heritabilities for NBT, NBA, NBD and LBWT were 0.020, 0.030, 0.088 and 0.196, respectively. Differences in the maternal heritability and the heritability for LBWT, a trait of the dam, are different due to accumulation of observations per litter. Maternal genetic effects are, therefore, of less importance than in highly selected European breeds.     

Effect of stage of gestation, litter size and uterine space on the incidence of mummified fetuses in pigs

Factors associated with incidence of mummified fetuses at 7, 9, 11, 13 and 15 wk of gestation were determined in a cross-sectional design involving 209 pregnant pigs. Percentage of observed mummies increased from 2.1 to 12.2% as gestation progressed. Incidence of mummies at 7 wk of gestation was not different between litters of nine fetuses or fewer and those of 10 fetuses or more. During the period of 7 to 15 wk of gestation, the incidence of mummies remained constant at about 1% in litters of nine fetuses or fewer, whereas in litters of 10 fetuses or more the incidence increased linearly from 1 to 12% (P less than .01). In litters of nine fetuses or fewer, a mummy occupied no less space than a live fetus until 13 wk of gestation. In litters of 10 fetuses or more, a mummy occupied less space than did a live fetus after 7 wk of gestation. An increase in the incidence of mummies in larger litters was associated with uterine space per fetus below that needed for development and survival. The 12% fetal loss in late gestation was associated with less uterine space per fetus. Length of uterine horns, litter size and stage of gestation together accounted for 12% of the variation in incidence of mummies (P less than .001). A longer uterus had greater space per fetus, a larger number of live fetuses and a lower incidence of mummies.     

Incidence of splayleg pigs in Nebraska litter size selection lines

Genetic parameters for the splayleg (SL) condition were estimated from 37,673 records of pigs from six lines derived from a Large White-Land-race base population. Random selection for 22 generations was practiced in Lines C1 and C2. Line C2 was derived from C1 at Generation 8. Selection lines were as follows: 1) Line I, selected 11 generations for an index of ovulation rate and embryonic survival followed by 11 generations of selection for litter size; 2) Line IOL, derived from Line I at Generation 8 and which underwent eight generations of two-stage selection for ovulation rate and number of fully formed pigs per litter followed by four generations of litter size selection; 3) Line COL, derived from Line C1 at Generation 8 and selected eight generations in two stages for ovulation rate and number of fully formed pigs followed by four generations of litter size selection; and 4) Line T, selected 12 generations for increased testis size. From logistic models, it was found that boars were 224% more likely to have SL than gilts (P < 0.01). Decreases in birth weight, dam age at puberty, dam nipple number, and dam embryonic survival, and increases in dam litter size and inbreeding increased the odds of SL (P < 0.05). Direct and maternal heritabilities of SL were 0.07 and 0.16, respectively, and the correlation between direct and maternal effects was -0.24. Correlations between direct genetic effects for SL and number born alive, nipple number, birth weight, age at puberty, and embryonic survival were -0.19, -0.36, 0.23, -0.19, and -0.32, respectively. Except for the correlation of 0.32 between maternal effects for SL and direct effects for number of live pigs, correlations of SL maternal genetic effects with direct genetic effects of other traits were less than 0.11. Annual direct genetic trends (%) for SL in I, IOL, COL, T, C1, and C2 were -0.003 +/- 0.003, 0.121 +/- 0.012, -0.273 +/-0.009, 0.243 +/-0.014, -0.274 +/-0.004, and 0.086 +/-0.008, respectively; annual maternal genetic trends (%) were 0.106 +/-0.004, 0.508 +/-0.019, 0.383 +/-0.015, 0.527 +/-0.024, 0.188 +/-0.005, and 0.113 +/-0.012, respectively. Annual genetic maternal trend in Line I after Generation 12 was 0.339 +/-0.014. Maternal breeding value for SL is expected to increase as a correlated response to selection for increased litter size and increased size of testes.     

High amino acid variation in the intracellular domain of the pig prolactin receptor (PRLR) and its relation to ovulation rate and piglet survival traits

Two polymorphisms of the porcine prolactin receptor (PRLR) gene were previously related to litter size by several authors; however, the magnitude and direction of such effects varied depending on the population analyzed. We have sequenced the complete coding region of the porcine PRLR gene and found 6 nonconservative SNP: C1217T (Leu/Pro406), C1283A (Asp/Ala428), G1439A (Lys/Arg480), T1528A (Met/Leu510), G1600A (Gly/Ser534), and G1789A (Gly/Ser597), within exon 10 of the gene, which encodes the entire intracytoplasmic domain of the protein. Eight haplotypes were found and were segregating at different frequencies in 6 porcine breeds. The effects of each individual SNP and haplotype were evaluated in an Iberian x Meishan F2 population using a univariate mixed-inheritance animal model. Significant effects on the number of corpora lutea were found for PRLR haplotypes (P < 0.012), confirming the previously reported associations of PRLR in this process and highlighting the importance of performing analysis of haplotypes rather than of individual SNP. Suggestive effects or tendencies were found for heart rate at birth (P < 0.10), rectal temperature (P < 0.05), and oxygen saturation (P < 0.10) 1 h after birth, and time to first suckle (P < 0.10). We found greater than expected levels of amino acid variability within the intracellular domain of the porcine PRLR, which have been associated with differences in the number of corpus lutea of sows and the preweaning survivability of piglets.     

叶酸对母猪产仔数的影响

叶酸即维生素 B11,它参与多种酶的活动 ,更重要的是与氨基酸和核苷酸的合成有关。多数研究结果表明 ,猪常用饲料的叶酸供给量 ,再加上肠道微生物合成的叶酸都可以满足各种猪的需求。但对于母猪补饲叶酸的效果尚存在争议。为了探讨叶酸对母猪繁殖力的影响 ,在漳州某猪场 ,用补饲的方法在断奶母猪的日粮中添加叶酸进行以下实验。1　材料与方法1 .1　实验猪　在本场选择长大二元杂交断奶母猪3 6头 ,按胎次品种随机分成对照组与实验组 ,每组1 8头。1 .2　日粮配制　含能量 70 5 k J,粗蛋白 1 5 .2 1 %,钙 0 .6 3 %,磷 0 .5 6 %,试验组在日粮中…     

Maternal influence mediated by litter size during the suckling period on reproduction traits in pigs

Maternal effects might affect the response to selection for litter size. An experiment was carried out to determine the effect of the size of litter in which a gilt was raised on its production and reproduction characteristics. Gilts raised in large litters (12 piglets) produced smaller litters (?0.48 piglets) compared to those raised in small litters (six piglets). Results obtained suggest that a low standardization level positively affects weaning weight and development of the uterus. Lower weight at weaning, in combination with a larger pool of primordial follicles, might explain the positive effect on litter size.     

Effect of exogenous progesterone and oestrone on litter size in swine

Three hundred sows and gilts on a large commercial unit were divided into four groups according to parity and either injected with corn oil on days 16 and 17 after service, injected with 25 mg progesterone and 12.5 micrograms oestrone on days 16 and 17 after service, or injected with these two hormones on either day 16 or day 17 after service. Animals injected with progesterone and oestrone on both the 16th and 17th days after mating had significantly (P less than 0.05) bigger litters at farrowing. Animals injected on the 17th day or on both the 16th and 17th days after mating had significantly shorter gestation periods (P less than 0.05). The treatments had no effect on the weaning to service interval or on the size of the subsequent litter.