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遗 传 学 报 ISSN 0379-4172 Acta Genetica Sinica, February 2006, 33 (2):117–124 Polymorphism of FecB Gene in Nine Sheep Breeds or Strains and Its Effects on Litter Size, Lamb Growth and Development GUAN Feng1,4, LIU Shou-Ren2, SHI Guo-Qing1, 2, AI Jun-Tao1, MAO Da-Gan1, YANG Li-Guo1,3,① 1. Research Institute of Animal Breeding & Reproduction, Nanjing Agricultural University, Nanjing 210095, China; 2. Institute of Animal Husbandry and Veterinary Medicine, Xinjiang Academy of Agricultural Reclamation, Shihezi 832000, China; 3. College of Animal Science, Huazhong Agricultural University, Wuhan 430070, China 4. College of Life Sciences, China Jiliang University, Hangzhou 310018, China Abstract: Nine sheep breeds or strains, including 615 individuals were screened with forced PCR RFLP method for the FecB gene to study the polymorphism and its effects on litter size, body weight and body size. Results showed that the polymorphism frequencies of FecB gene were significantly imbalanced in these breeds or strains. The Hu sheep were all homozygous carriers of FecB gene(BB). In the Chinese Merino prolific meat strain, the genotype frequencies of BB, B+ and ++ were 51%, 30% and 19%, respectively, whereas all the other flocks had only the wild-type (++) genotype. Results within the Chinese Merino prolific meat strain showed that the mean litter size of ewes with genotype BB and B+ were 2.8 (±0.74) and 2.3 (±0.63) (P<0.05), whereas ++ genotype ewes had a litter size of only 1.2 (±0.68) (P<0.01). At day 90 after birth, the body weights of BB/B+ genotype lambs were higher than that of ++ genotype lambs (18.6±3.70 kg, 18.0±3.71 kg vs 15.6±2.22 kg, P<0.05). In addition, the heart girth and chest width of BB/B+ genotype lambs were significantly longer than those of the ++ lambs (P<0.05). No significant differences were observed in either body weight or body size at day 120. Litter size at first lambing from Hu at Natural Source Conservative Region was found to be significantly higher than that from the other two regions sampled (P<0.05). In addition to the additive effect on litter size, these findings showed for the first time that the FecB gene had a positive effect on early postnatal body growth. Key words: sheep; FecB gene; litter size; body weight; body size Litter size and lamb growth are important economic traits in sheep breeding and reproduction. Recently, it has been reported that bone morphogenetic protein receptor IB (BMPR-IB) gene mutation was responsible for the high prolificacy associated with the FecB gene in Booroola Merino sheep [1-3]. This mutation is located in the highly conserved kinase domain of BMPR-IB, and mutant sheep are characterized by ‘precocious’ differentiation of ovarian follicles, leading to the production of large numbers of ovulatory follicles that are smaller in diameter than wild-type follicles [4]. This mutation can be detected directly by a forced PCR restriction fragment length polymorphism (RFLP) approach based on the reports described by Souza et al. [2] and Davis et al [5]. In recent years, many aspects of the FecB gene, including reproductive endocrinology [6] , ovarian de- [7] velopment , litter size, organ development and body mass [8] have been studied. This gene has additive effect on litter size and ovulation rate, but has negative effect on fetal growth and development and body mass during gestation. For example, body weights Received: 2004-11-30; Accepted: 2005-04-03 This work was supported by the Natural Science Foundation of Zhejiang Province of China (No.Y 305107) and Shanghai Key Project of Science and Technology Service for Agriculture(No.2002, 1-3-6). ① Corresponding author.Tel: +86-27-8728 1813; E-mail: [email protected] 118 Acta Genetica Sinica 遗传学报 were lighter (P<0.05) at most gestational ages in BB/B+ than in ++ fetuses [6] ral Resource Conservative Region in 1982 and after [9] several generations of strict selection, its litter size . It was reported that FecB gene had been detected in Hu Since the establishment of Dongshan Hu-sheep Natu- , and crown-rump length was shorter in BB/B+ than in ++ fetuses [10] Vol.33 No.2 2006 and small tailed Han [11] in China, and that it could be a major gene affecting the litter size of small tailed Han sheep. Both Hu and Small Tailed Han are Chinese breeds that are among the most prolific sheep breeds in the world [12]. Several sheep breeds have been introduced into China in recent years and crossed with local sheep. The distribution of the FecB mutation of the BMPR-IB gene and its effects on body weight and body sizes in these sheep flocks are unknown. The objective of this paper is to study the frequency distributions of FecB in different breeds or strains in China, and evaluate the effects of the FecB gene on (2.256 vs 2.567) and body weight have improved significantly (P<0.05)[15]. Chinese Merino prolific meat strain has been bred by Xinjiang Academy of Agricultural Reclamation since 1981, via reciprocal crossing of Hu with Chinese Merino fine wool prolific flocks on the basis of phenotype selection. After several generations of selection, the strain has stabilized to being 1/4 Hu and 3/4 Chinese Merino. 1. 2 Primer synthesis and PCR-RFLP reactions Primers were synthesized by Shanghai Sangon Biotech Co. Ltd based on the sequences described by Wilson et al [3] . DNA tests were carried out using litter size, and body weights and body sizes after birth. forced PCR RFLP based on the method described by 1 Forward primer: 5′-CCAGAGGACAATAGCAAAG- Davis et al [5]. The primers were designed as follows: Materials and Methods 1. 1 CAAA-3′; Reverse primer: 5′-CAAGATGTTTTCAT- Experimental sheep flocks and sampling GCCTCATCAACAGGTC-3′. A total of 615 sheep individuals were examined The reverse primer deliberately introduced by a in this study from nine breeds or strains, including Hu, point mutation which would create an AvaⅡ restric- Suffolk, Dorset, Charolais, Chinese Merino prolific tion site (G|GACC) in PCR products from FecB car- meat strain, Romney Hills, Merino, and crossbreed of rier sheep, whereas PCR products from the noncarri- Suffolk × Chinese Merino as well as Dorset × Chi- ers lacked this site. nese Merino. Hu-sheep samples were collected from Genomic DNA (50-100 ng) was used in a 20 μL farms in central production areas including farms in of reaction volume. The amplification was carried out Shanghai, Suzhou and Dongshan Hu-sheep Natural by 30 cycles at 94℃ for 30 s, 60℃ for 30 s, and 72℃ Resource Conservative Region in Jiangsu province. for 30 s followed by 72℃ for 5 min. The PCR prod- The other breeds were sampled from Xinjiang Agri- ucts were digested with AvaⅡ (Dalian TaKaRa Bio- culture No.6 Sheep Farm. After sterilization with 70% ethanol about 5 g of skin tissue was cut from the ovine ear with a clamp. All samples were taken back to the laboratory under low temperature. The genomic DNA was extracted according to methods described by Molecular Cloning [13] , and stored at -20℃ before use. tech Co.,Ltd, China) overnight at 37℃, and the resulting products were separated by 12% PAGE gel and visualized with silver staining. 1. 3 Genotype analysis The forced PCR of the FecB gene produced a 190 base pair (bp) band. The FecB gene homozygous The Hu is the predominant breed in Suzhou, carriers could be identified as having a 160 bp band Shanghai and Dongshan where they are well adapted (BB), the noncarriers as having a 190 bp band (++), to the hot and humid environment. Dongshan, near the whereas and the heterozygotes as having both the 160 Tai lake, is one of the original sources of Hu-sheep [14] . and 190 bp bands (B+). GUAN Feng et al.: Polymorphism of FecB Gene in Nine Sheep Breeds or Strains and Its Effects on Litter Size,…… 1. 4 Statistical analysis All the records of body sizes and weights were measured according to methods described by LIU Zhen-Yi [16]. All data including mean litter size were presented as x ±SD. The non-informative individuals were excluded. Body weight and body size data were analyzed by one-way ANOVA. 119 Table 1 Frequency distributions of FecB gene in nine sheep breeds or strains No. of samples Breed or strain Genotype frequency BB B+ ++ Hu sheep 305 1 0 0 Chinese Merino prolific Meat strain 53 0.51 0.30 0.19 Suffolk sheep 22 0 0 1 Dorset sheep 56 0 0 1 Charolais sheep 21 0 0 1 Suffolk×China Merino 36 0 0 1 Dorset×China Merino 49 0 0 1 Results of FecB gene PCR products after AvaⅡ China Merino 24 0 0 1 digestion can be seen in Fig.1. Thus this PCR-RFLP technique can be used to detect and genotype FecB gene clearly. Romney Hills 49 0 0 1 2 Results 2. 1 Results of PCR-RFLP electrophoresis 2. 3 Comparison of litter size To eliminate error from different breeds and strains and other effects, comparison of litter size, body weight and body size was confined to the Chinese Merino prolific meat strain. Within this strain, the litter size of ewes with the BB genotype averaged 2.84±0.74, which was significantly greater than that Fig. 1 PCR-RFLP genotyping of FecB gene in sheep Lanes 1-3 and 5-9 are AvaⅡ-digested PCR products of either 190 bp (representing genotype ++) or 160 bp (genotype BB); Lane 4 is the pBR322/MspⅠ DNA Marker (labeled as M). 2. 2 Frequency distributions of FecB gene in different breeds or strains A total of 615 individuals from nine different breeds or strains were screened by the forced PCR-RFLP approach. Results (Table 1) showed that the frequency of polymorphism distributions of FecB gene was most imbalanced in these breeds or strains. Chinese Merino prolific meat strain had three different Booroola genotypes (BB, B+ and ++), and their frequencies were 51%, 30% and 19%, respectively. In contrast, Hu were all homozygous for FecB (BB) whereas the other breeds all had the wildtype allele (++). In addition, we found that Hu-sheep crossbred progenies had a B+ genotype, which exhibited a simple Mendelian pattern of segregation when they were backcrossed. of ewes with the ++ genotype (1.23±0.68, P<0.01, Table 2). The ewes with the BB genotype also produced 0.5 lambs more than ewes with the B+ genotype, although the difference was not statistically significant. Table 2 Comparison of litter size among three genotypes of Chinese Merino meat-prolific strain ewes at parity Genotype BB B+ ++ No. of sample 27 16 10 Mean litter size 2.84±0.74A 2.34±0.63A 1.23±0.68B Note: In this table and throughout, values (mean ± SD) in the same line with different superscripts are statistically different from each other, with small letters indicating P<0.05 and with capital letter indicating P<0.01. 2. 4 Body weight and body size in flocks with different genotypes Body weight and body size are important indices of body growth and breeding traits. In this study, the results showed that the mean body weight of BB 120 遗传学报 2. 5 Table 3 Comparison of body weight of ewes at ages 90 and 120 days among three genotypes BB B+ ++ 27 16 10 Birth weight(kg) 3.4±0.47 3.4±0.87 3.3±0.78 Body weight(kg) at 90 days 18.6±3.70a 18.0±3.31a 15.6±2.22b Body weight(kg) at 120 days 23.5±4.95 23.0±5.00 22.6±3.68 No. of samples 3 Discussion RFLP is a rapid, simple and exact technique Comparison of body size at ages 90 and 120 days Genotype No. of sample Age Litter size among Hu-sheep from different sources in China The results of genotyping in this study are fully consistent with previous studies in our laboratory [10]. There was no difference in total mean litter size among the different flocks in the three sample sources (Table 5). And no difference was detected between the second and the third lambing, but in Dongshan Hu sheep Natural Resource Conservative Region, the mean litter size at first lambing was significantly higher than that of sheep from the other two regions (P<0.05). The differences in heart girth and chest width were only significant between the flocks with carrier (BB/ B+) and noncarrier (++) genotypes at 90 Table 4 Vol.33 No.2 2006 days of age (P<0.05, Table 4). There were no significant differences among different genotypes in other body size measures at 90 days or in any parameters at 120 days. and B+ lambs were significantly higher (P<0.05) than that of ++ lambs at 90 days of age (Table 3). No significant differences were found between either BB and B+ or B+ and ++ flocks by day 120. Genotype Acta Genetica Sinica B+ ++ 27 16 10 90 120 90 120 90 120 Body length (cm) 53.6±3.82 55.6±3.90 54.0±4.88 55.6±4.08 50.4±2.94 55.6±3.91 Body height (cm) 53.6±3.43 55.8±4.24 52.5±4.20 55.7±3.77 50.6±2.88 55.6±3.67 Heart girth (cm) 63.8±4.62a 69.1±6.29 61.2±4.42a 69.3±6.34 58.6±3.21b 68.4±6.16 Chest depth (cm) 23.1±2.08 26.0±2.00 22.1±1.75 25.8±1.90 21.1±1.78 25.8±1.87 Chest width (cm) 16.0±1.33 a 17.6±1.71 16.0±1.10 a 17.5±1.69 14.6±1.31 b 17.4±1.63 Cannon girth (cm) 6.9±0.44 7.2±0.53 6.9±0.65 7.1±0.39 6.6±0.48 Table 5 (days) BB 7.1±0.41 Comparison of litter size in different sources of samples Source of samples No. of sample Litter size at 1-3 lambing Suzhou Shanghai Dongshan Total 91 67 87 245 2.21±1.00 2.10±0.74 2.37±0.74 2.24±0.87 Mean litter size at 1st lambing 1.90±0.90 a 1.78±0.64 a 2.12±0.67 b 1.92±0.73a Mean litter size at 2nd lambing 2.43±0.95 2.23±0.75 2.56±0.62 2.45±0.87 Mean litter size at 3rd lambing 2.54±1.11 2.36±0.50 2.80±1.01 2.56±1.00 GUAN Feng et al.: Polymorphism of FecB Gene in Nine Sheep Breeds or Strains and Its Effects on Litter Size,…… 121 for single nucleotide polymorphism (SNP) genotyping. After a forced restriction site was introduced into one of the primers, the PCR product contained a certain restriction enzyme site. This forced PCR-RFLP approach has been used previously to genotype prolific sheep [2,5] and swine [17] to decide whether they had the same mutation as FecB in Booroola Merino sheep. In our experiments, we used such an approach FecB mutation (Q249R) in BMPR-IB gene was found, the ewes were classified as homozygous, heterozygous and noncarriers and could be segregated on the basis of ovulation rate records of five or more, three or four, and one or two, respectively [19]. But in our experiment, a forced PCR-RFLP method was applied for genotyping. It was reported that the FecB gene has negative and PAGE to detect the genotypes based on the effects on fetal body weight, body size and develop- [5] . ment during pregnancy [6]. Body weights were lighter Results in Fig. 1 show that this method could be used at most gestational ages in BB/B+ than in ++ fetuses, to accurately genotype the FecB gene. Illegible or and the BB/B+ grew slowly and body lengths were inconclusive results were repeated until the genotyp- shorter than ++ fetuses. In contrast, when measuring ing was clear, or they were excluded from the data postnatal growth and development our results showed analysis. that by day 90 after birth, body weight, heart girth, method described by Souza et al. [2] and Davis et al It has been well known that Hu and Chinese and body height were significantly increased in Merino prolific meat sheep are highly prolific, and BB/B+ compared with ++ lambs. The BB and B+ Chinese Merino and Romney Hills are more prolific lambs of similar birth weight grew more in the first in comparison with many other breeds. Findings 90 days after birth. The differences probably resulted concerning Hu sheep that has only a single BB geno- from the effects of different breeds and different type are not in agreement with other reports about phases of development, environmental conditions, Booroola sheep, in which three genotypes have been different lambing and nutrition, or other factors alto- observed. The phenomenon probably resulted from the whole process of Hu sheep establishment, result- gether. The mechanism requires further research. To date, in addition to BMPR-IB (FecB) and ing in the gene being fixed in the Hu population, just BMP15 gene mutations as it has also been observed in some Garole sheep of Booroola sheep and Inverdale or Hanna sheep, populations in India [5]. there is evidence that other major genes or QTLs may It was reported that the effect of FecB gene is additive for litter size and ovulation rate, increasing ovulation by about 1.65 per copy and litter size by 0.9 for one copy and a further 0.4 for two copies [18]. Our results showed that based on litter size, the effect of the FecB gene in Hu sheep and its crossbreds is similar to that reported in Booroola sheep. Although ovulation rates have not been measured in the Hu sheep, the litter size effects are consistent with other studies of the Booroola gene (FecB), which have shown that it has a large effect on ovulation rate. The mean litter size previously reported in Booroola sheep is higher than that of Chinese Merino prolific meat strain and Hu sheep, which probably resulted from different breeds, environments, maternal nutrition, seasons and method for genotyping. Before the be segregated from Icelandic sheep, Javanese sheep, [20] influencing ovulation rate Olkuska, Cambridge, Lacaune, Belclare and Woodlands sheep breeds [21]. But BMP15 mutation has not been found in most individuals in our study based on the method described by Galloway et al [20] . The Thoka gene has been found to be a major gene in Iceland sheep, and has the similar mechanism with FecB gene but not FecB or BMP15 genes [5] . The Thoka gene has additive effect on ovulation, increasing ovulation rate by about 1.21 or more and litter size by 0.6 [22] . The FecJ gene was a major gene segregating in Javanese thin tailed sheep and has a smaller additive effect on litter size and ovulation rate than that of the FecB gene [23]. Davis et al. [5] subsequently found that the FecJ gene was the same mutation as FecB. The effect of a major gene on 122 mean litter size is likely to be influenced by breed, environmental conditions, maternal nutrition and other factors. Muslant et al. [1] and Wilson et al. [3] reported that FecB is a major gene inherited as a single autosomal locus, which regulates ovulation rate of Booroola sheep. Using DNA testing we also found that the FecB gene followed Mendelian segregation patterns in Hu sheep and crossbreds. Davis et al.[5] proposed the Garole sheep of India as the ancestor of Australian Booroola Merinos based on historical records and evidence that they had the same BMPR-IB gene mutation. The Hu and its crosses were the only breeds in our study that carried the FecB mutation. Research has shown that the Hu and Han are closely related and both descend from ancient Mongol Sheep [24]. We found that Hu-sheep have a higher litter size at first lambing in Nature Source Conservative Region than those from the other two regions, which probably resulted from the method of breeding. Traditionally, sheep were maintained in family flocks of about three or four ewes, many families relying on neighbors for a ram in a village. The aim of breeding was high prolificacy and high quality of lambskins. Ewes and rams were selected on the basis of these traits because this region was famous for Hu-sheep lambskins. Traditionally, the farmer sold excellent individuals and retained lower quality individuals. Later when exportation of lambskins was resisted in 1980s, the excellent individuals were retained, which is the major reason for high prolificacy and fast growth in this breed. Hu have a single BB genotype, but the litter size of the first lambing is significantly different between Hu sheep from different flocks. Whether other gene(s) or quantitative trait loci (QTL) regulating ovulation are also present requires further research. We propose that this difference probably is the consequence of different environmental conditions, nutrition, selection, and possibly even QTL or gene(s) regulating sexual maturity and ovulation rate. Acknowledgement: We thank the farmers for collection of samples in Xinjiang Agriculture No.6 farm 遗传学报 Acta Genetica Sinica Vol.33 No.2 2006 and Xinjiang Academy of Agricultural Reclamation for providing the laboratory. We thank Mr. Davis GH in NewZealand for advice and amending this paper. References: [1] Mulsant P, Lecerf F, Fabre S, Schibler L, Monget P, Lanneluc I, Pisselet C, Riquet J, Monniaux D, Callebaut I. Mutation in bone morphogenetic protein receptor-IB is associated with increased ovulation rate in Booroola Merino ewes. Proc Natl Acad Sci USA, 2001, 98 : 5104-5109. [2] Souza C J, MacDougal C, Campbell B K, McNeilly A S, Baird D T. The Booroola (FecB) phenotype is associated with a mutation in the bone morphogenetic receptor type IB (BMPR-IB) gene. J Endocrinol, 2001, (2) : R1-6. [3] Wilson T, Wu X L, Juengel J L, Ross I K, Lumsden J M, Lord E A, Dodds K G, Walling G A, McEwan J C, O’Connell A R, McNatty K P, Montgomery G W. Highly prolific Booroola sheep have a mutation in the intracellular kinase domain of bone morphogenetic protein IB receptor (ALK-6) that is expressed in both oocytes and granulosa cells. Biology of Reproduction, 2001, 64 : 1225-1235. [4] Souza C J, Campbell B K, Webb R, Baird D T. Secretion of inhibin A and follicular dynamics throughout the estrous cycle in the sheep with or without the Booroola gene (FecB). Endocrinology, 1997, 138 : 5333-5340. [5] Davis G H, Galloway S M, Ross L K, Gregan S M, Ward G, Nimbkar B V, Ghalsasi P M. DNA tests in prolific sheep from eight countries provide new evidence on origin of the Booroola (FecB) mutation. Biology of Reproduction, 2002, 66 : 1869-1874. [6] Smith P, O W S, Hudson N L, Shaw L, Heath D A, Condell L, Phillips D J, McNatty K P. Effects of the Booroola gene (FecB) on body weight, ovarian development and hormone concentrations during fetal life. J Reprod Fertil, 1993, 1 : 41-54. [7] Cognie Y, Benoit F, Poulin N, Khatir H, Driancourt M A. Effect of follicle size and of the FecB Booroola gene on oocyte function in sheep. J Reprod Fertil, 1998, 2 : 379-86. [8] Smith P, Hudson N L, Corrigan K A, Shaw L, Smith T, Phillips D J, McNatty K P. Effects of the Booroola gene (FecB(B)) on body mass, testis development and hormone concentrations during fetal life. Reprod Fertil, 1996, 2 : 253-61. [9] McNatty K P, Smith P, Hudson N L, Heath D A, Tisdall D J, O W S, BrawTal R. Development of the sheep ovary during fetal and early neonatal life and the effect of fe- GUAN Feng et al.: Polymorphism of FecB Gene in Nine Sheep Breeds or Strains and Its Effects on Litter Size,…… 123 cundity genes. Journal of Reproduction and Fertility tion and expression of porcine bone morphogenetic pro- Supplement, 1995, 49 : 123-135. tein receptor-IB in the uterus of cyclic and pregnant gilts. [10] WANG Gen-Lin, MAO Xin-Zhi, Davis G H, ZHAO Biology of Reproduction, 2003, 68 : 735-743. Zong-Sheng, ZHANG Li-Jun, ZENG Yong-Qing. DNA [18] Piper L R, Bindon B M, Davis G H. The single gene in- tests in Hu sheep and Han sheep (small tail) showed the heritance of the high litter size of the Booroola Merino. In: existence of Booroola (FecB) mutation. Journal of Nan- Genetics of reproduction in sheep. Butterworths, London, jing Agricultural University, 2003, 26(1) : 104-106(in 1985, 115-125. Chinese with an English abstract). [11] LIU Shu-Fang, JIANG Yun- Liang, DU Li-Xin. Study of [19] Davis G H, Montgomery G W, Allison A J. Segregation of a major gene influencing fecundity in progeny of BMPR-IB and BMP15 as candidate gene for fecundity in Booroola sheep. New Zealand J of Agricultural Research, little tailed Han sheep. Acta Genetica Sinica, 2003, 30(8) : 1982, 25 : 525-529. 755-760(in Chinese with an English abstract). [12] Fahmy M H. Prolific sheep. Wallingford, UK: CAB International, 1996. [13] Sambrook J, Fritsh E F, Maniatis T. Translated by JIN [20] Galloway S M, McNatty K P, Cambridge L M, Laitinen M P, Juengel J L, Jokiranta T S, McLaren R J, Luiro K, DoddsK G, Montgomery G W, Beattie A E, Davis G H, Ritvos O. Mutation in an oocyte-derived growth factor Dong-Yan. Molecular cloning: a laboratory manual. 2nd gene (BMP15) cause increased ovulation rate and infer- ed. Beijing: Science Press, 1998(in Chinese). tility in a dosage-sensitive manner. Nature Genetics, 2000, [14] GENG Rong-Qing, CHANG Hong, YANG Zhang-Ping, SUN Wei, WANG Lan-Ping, LU Sheng-Xia, Ken Ji TSUNODA. Study on origin and phylogeny status of Hu sheep. Jour of Northwest Sci-Tech Univ of Agri and For (Nat and Ed) , 2002, 30(3) : 21-28(in Chinese with an English abstract). [15] WANG Yuan-Xing, WANG Cheng, CHENG Rui-He, WANG Yan-Shu, WU Jian-Xin, SHEN Bu-Gen. The characteristics and approach for improvement of Hu sheep in Jiangsu province Wu country Hu sheep conservative region. Ecology of Domestic Animal, 1998, 19 (3) : 26-28(in Chinese with an English abstract). [16] LIU Zhen-Yi. Domestic animal breeding . 2nd ed. Beijing: China Agricultural Press, 1998(in Chinese). [17] Kim J H, Song J H, Vallet J L, Rohrer G A, Johnson G A, Margaret M M, Christenson R K. Molecular characteriza- 25 : 279-283. [21] Montgomery G W, Galloway S M, Davis G H, McNatty K P. Genes controlling ovulation rate in sheep. Reproduction, 2001, 121 : 843-852. [22] Jonmundosson J V, Adalstinsson S. Single genes for fecundity in Icelandic sheep. Genetics of Reproduction in Sheep, 1985 : 159-168. [23] Roberts J A. Frequency of the prolificacy gene in flocks of Indonesian thin tail sheep: a review. Small Ruminant Research, 2000, 36 : 215-226. [24] GONG Yuan-Fang, LI Xiang-Long, LIU Zheng-Zhu, LI Jin-Quan. Studies of random amplified polymorphic DNA (RAPD) of main indigenous sheep breeds in China. Hereditas (Beijing), 2002, 24(4) : 423-426(in Chinese with an English abstract). 124 遗传学报 Acta Genetica Sinica Vol.33 No.2 2006 FecB 基因在 9 个绵羊品种中的多态性及其与产羔数和羔羊生 长发育的相关性 管 峰 1,4,刘守仁 2,石国庆 1,2,艾君涛 1,茆达干 1,杨利国 1,3 1. 南京农业大学动物繁育研究所,南京 210095; 2. 新疆农垦科学院畜牧兽医研究所,石河子 832000; 3. 华中农业大学动物科技学院,武汉 430070; 4. 中国计量学院生命科学学院,杭州 310018 摘 要:以绵羊 BMPR-IB 基因为候选基因,应用 PCR-RFLP 方法通过分析湖羊、夏洛来、陶赛特、萨福克、罗米丽、中国 美利奴羊、中国美利奴肉用多胎品系以及陶赛特×中国美利奴羊和萨福克×中国美利奴羊杂交后代共 615 只个体的 FecB 基因多态性,以及 BMPR-IB 基因多态性对产羔数、体尺和体重的影响。结果表明,BMPR-IB 基因在不同品种(系)绵羊 中共有 3 种基因型(BB、B+和++),但基因型频率分布在各品种(系)间差异极显著(P<0.01)。在湖羊中仅有 BB 基因型;在 中国美利奴肉用多胎品系中 BB、B+和++基因型频率分别为 51%、30%和 19%;而其他品种(系)羊中则仅有++基因型。 对中国美利奴羊肉用多胎品系研究,发现 BB 和 B+基因型群体平均产羔数分别为 2.8 和 2.3,显著高于++基因型群体(1.2, P<0.01) 。在 90 日龄时,BB 和 B+基因型群体的体重分别为 18.6±3.70 kg 和 18.0±3.31 kg,显著高于++基因型群体(15.6 ±2.22 kg,P<0.05);此外,90 日龄时,BB 和 B+基因型群体比++基因型群体胸围、胸宽较大(P<0.05);但这些差异在 120 日龄时消失。另外,我们还发现不同地区群体的第一胎产羔数存在明显差别。这些结果表明,BMPR-IB 基因为影响绵 羊产羔数的主效基因,并首次证明该基因对后代羔羊出生后生长发育具有加性效应。 关键词:绵羊;BMPR-IB 基因;产羔数;体重;体尺 作者简介:管 峰(1977-),男,博士,研究方向:动物分子标记育种。现工作单位:中国计量学院生命科学学院