Abstract
Using genomic data, lethal recessives may be discovered from haplotypes that are common in the population but never occur in the homozygote state in live animals. This approach only requires genotype data from phenotypically normal (i.e. live) individuals and not from the affected embryos that die. A total of 7,937 Nordic Holstein animals were genotyped with BovineSNP50 BeadChip and haplotypes including 25 consecutive markers were constructed and tested for absence of homozygotes states. We have identified 17 homozygote deficient haplotypes which could be loosely clustered into eight genomic regions harboring possible recessive lethal alleles. Effects of the identified haplotypes were estimated on two fertility traits: non-return rates and calving interval. Out of the eight identified genomic regions, six regions were confirmed as having an effect on fertility. The information can be used to avoid carrier-by-carrier mattings in practical animal breeding. Further, identification of causative genes/polymorphisms responsible for lethal effects will lead to accurate testing of the individuals carrying a lethal allele.
Highlights
Alleles that cause an organism to die only when present in homozygous state are called recessively lethal alleles
Lethal recessives may be discovered from haplotypes that are common in the population but never occur in the homozygote state in live animals [1]
Fritz et al [2] used the same approach in three French cattle breeds and identified a number of genomic regions showing a deficit in homozygotes
Summary
Alleles that cause an organism to die only when present in homozygous state are called recessively lethal alleles. Genotyping technology enables population researchers to genotype thousands of SNPs to cover the whole genome With this genomic data, lethal recessives may be discovered from haplotypes that are common in the population but never occur in the homozygote state in live animals [1]. Lethal recessives may be discovered from haplotypes that are common in the population but never occur in the homozygote state in live animals [1] This approach only requires genotype data on phenotypically normal (i.e. live) individuals and not on the affected embryos that die. Following this approach VanRaden et al [1] discovered 5 recessive lethal haplotypes in 3 cattle breeds.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
