Genotype and Allelic Frequencies of a Newly Identified Mutation Causing Blindness in Jordanian Awassi Sheep Flocks

Abstract

A total of 423 blood samples were collected (during 2009 and 2010) from all the ram holdings at three major Jordanian governmental Awassi breeding stations (Al-Khanasry, Al-Mushairfa and Al-Fjaje) and two private flocks. All blood samples were screened for the presence of mutations at the CNGA3 gene (responsible for day blindness in Awassi sheep) using RFLP-PCR. The day blindness mutation was detected in all studied flocks. The overall allele and genotype frequencies of all studied flocks of the day blindness mutation were 0.088 and 17.49%, respectively. The genotype and allele frequencies were higher in station flocks than the farmer flocks (0.121, 24.15 and 0.012, 2.32, respectively). Al-Mushairfa and Al-Khanasry stations have the highest genotype and allele frequencies for the day blindness mutation that were 27.77, 30.00% and 0.14, 0.171, respectively. The investigated farmer flocks have low percentages (0.03, 5.88% at Al-Shoubak and 0.005 and 1.05%, at Al-Karak, respectively for genotype and allele frequencies) compared with the breeding stations. Ram culling strategy was applied throughout the genotyping period in order to gradually eradicate this newly identified day blindness mutation from Jordanian Breeding station, since they annually distribute a high percentage of improved rams to farmer’s flocks.

Polymorphism of prolactin, growth differentiation factor 9 and calpastatin genes and their effects on pre-weaning growth traits in Awassi lambs

“…To guarantee the quality of the analyses, data were edited and abnormal records or out of biological limit were deleted. Gene and genotype frequencies and the Hardy–Weinberg test (based on Chi-square test) were calculated as previously described [1].…”

“…Sheep are considered an important source of livelihoods in many countries in the Middle East. Awassi sheep or fat-tailed sheep are hardy and multipurpose breed that is kept for meat, milk, and wool production [1,2]. Growth performance of lambs is one of the most detrimental factors of meat production.…”

“…In fact, strong relationships have been determined between the marketing weights and different growth traits in lambs, including birth and weaning weights and average daily gain (ADG) [2,3]. Therefore, selection for these traits in the early stages of the animal’s life may result in the overall improvement of the animal’s productivity [1].…”

The allele frequencies of growth hormone gene on the parental and progeny of Ongole-crossbreed cattle population in the North Sulawesi of Indonesia using PCR-RFLP

“…Krista with genotype of Msp1+/+. Jawasreh et al (2012) reported that breeding program must be continued as the first step to increase the frequency of the favorable allele in breeding station. Genotypic selection of bulls was the main strategy for distribution of improved animals to the farmers.…”

Detection of Mendelian and Genotype Frequency of Growth Hormone Gene in Ongole Crossbred Cattle Mated by the Artificial Insemination Technique

“…The factor affecting genetic equilibrium was selection program with non random mating system, such as the artificial insemination mating system (Van Vleck et al, 1987). Jawasreh et al (2012) reported that breeding program must be continued as the first step to increase the frequency of the favorable allele in breeding station. In North Sulawesi province, the artificial insemination service center applied the straw containing spermatozoa germplasm of Ongole bull called "Krista" and "Tunggul" from germplasm center (Balai Besar Inseminasi Buatan) Singosari, East Java province.…”