Single gene and gene interaction effects on fertilization and embryonic survival rates in cattle

Decrease in fertility and conception rates is a major cause of economic loss and cow culling in dairy herds. Conception rate is the product of fertilization rate and embryonic survival rate. Identification of genetic factors that cause the death of embryos is the first step in eliminating this probl...

Full description

Saved in:

Bibliographic Details
Published in:	Journal of dairy science Vol. 92; no. 5; p. 2238
Main Authors:	Khatib, H, Huang, W, Wang, X, Tran, A H, Bindrim, A B, Schutzkus, V, Monson, R L, Yandell, B S
Format:	Journal Article
Language:	English
Published:	United States 01-05-2009
Subjects:	Animals Cattle - genetics Embryo, Mammalian Epistasis, Genetic - genetics Female Fertility - genetics Fertilization - genetics Genotype In Vitro Techniques Lactation - genetics Male Milk - secretion Survival Analysis Transcription Factor Pit-1 - genetics
Online Access:	Get more information
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Decrease in fertility and conception rates is a major cause of economic loss and cow culling in dairy herds. Conception rate is the product of fertilization rate and embryonic survival rate. Identification of genetic factors that cause the death of embryos is the first step in eliminating this problem from the population and thereby increasing reproductive efficiency. A candidate pathway approach was used to identify candidate genes affecting fertilization and embryo survival rates using an in vitro fertilization experimental system. A total of 7,413 in vitro fertilizations were performed using oocytes from 504 ovaries and semen samples from 10 different bulls. Fertilization rate was calculated as the number of cleaved embryos 48 h postfertilization out of the total number of oocytes exposed to sperm. Survival rate of embryos was calculated as the number of blastocysts on d 7 of development out of the number of total embryos cultured. All ovaries were genotyped for 8 genes in the POU1F1 signaling pathway. Single-gene analysis revealed significant associations of GHR, PRLR, STAT5A, and UTMP with survival rate and of POU1F1, GHR, STAT5A, and OPN with fertilization rate. To further characterize the contribution of the entire integrated POU1F1 pathway to fertilization and early embryonic survival, a model selection procedure was applied. Comparisons among the different models showed that interactions between adjacent genes in the pathway revealed a significant contribution to the variation in fertility traits compared with other models that analyzed only bull information or only genes without interactions. Moreover, some genes that were not significant in the single-gene analysis showed significant effects in the interaction analysis. Thus, we propose that single genes as well as an entire pathway can be used in selection programs to improve reproduction performance in dairy cattle.
ISSN:	1525-3198
DOI:	10.3168/jds.2008-1767