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Molecular markers in the LEP gene and reproductive performance of beef cattle
Author(s) -
Almeida S. E. M.,
Almeida E. A.,
Moraes J. C. F.,
Weimer T. A.
Publication year - 2003
Publication title -
journal of animal breeding and genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.689
H-Index - 51
eISSN - 1439-0388
pISSN - 0931-2668
DOI - 10.1046/j.1439-0388.2003.00377.x
Subject(s) - biology , breed , beef cattle , genetics , allele , reproduction , marker assisted selection , genotype , herd , ice calving , genetic diversity , microsatellite , restriction fragment length polymorphism , genetic marker , zoology , gene , pregnancy , lactation , population , demography , sociology
Summary The present study investigated four restriction fragment length polymorphisms (RFLPs) in the leptin gene and five short tandem repeats (STRs) in its vicinity in 160 females from a synthetic beef cattle breed (5/8 Aberdeen Angus and 3/8 Nelore), and evaluated possible associations between these markers and reproductive performance. A high level of genetic diversity was observed, STRs being more variable than RFLPs. Heterozygosities ranged from 0.67 to 0.87 in STRs and from 0.12 to 0.49 in RFLPs, suggesting that the selective process applied to the Brangus‐Ibage cattle had not affected the total genetic diversity expected for crossbreeds. Two alleles ( IDVGA51*181 and LEPSau3A1 *+) seem to increase calving interval (CI) by about 79 and 81 days, respectively. Therefore, selection against carriers of these mutations could improve CI by at least 2 months, despite the seasonality of the mating period employed here. LEPSau3AI system seems to influence weight at first calving (WFC). Heterozygotes ( LEPSau3AI *+/ LEPSau3AI *−) had higher WFC than LEPSau3AI *−/ LEPSau3AI *− homozygote. Selection for animals with this genotype could result in some advantages for post‐calving recovery. CI and WFC are indirect measurements of reproduction reflecting also animal body conditions, and therefore it is difficult to determine whether or not IDVGA51*181 and LEPSau3A1 *+ alleles directly affect the reproductive system. Although further analysis of other herds should be performed to confirm these data, the association of genetic markers with better reproductive performance is a very interesting finding and could be used in marker‐assisted selection to improve reproduction in beef cattle.