بررسي تنوع اگزون 4 ژن هورمون رشد و ارتباط آن با صفات شير و چندقلوزايي در بزهاي خلخالي

Investigation of Diversity in Exon 4 of Growth Hormone Gene and Relationship with Milk traits and Litter Size in Khalkhali Goats

ﭼﮑﯿﺪه اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﺎ ﻫﺪف ﺑﺮرﺳﯽ ﺗﻨﻮع ژﻧﺘﯿﮑﯽ در ژن ﻫﻮرﻣﻮن رﺷﺪ و ارﺗﺒﺎط آن ﺑﺎ ﺗﻮﻟﯿﺪ ﺷﯿﺮ و ﭼﻨﺪﻗﻠﻮزاﯾﯽ در 120 رأس از ﺑﺰﻫﺎي ﺷﯿﺮي ﺧﻠﺨﺎﻟﯽ اﻧﺠﺎم ﮔﺮﻓﺖ. ﺑﺮاي اﻧﺠﺎم اﯾﻦ ﻣﻄﺎﻟﻌﻪ از روش PCR-SSCP ﺟﻬﺖ ﺷﻨﺎﺳﺎﯾﯽ اﻟﮕﻮﻫﺎي ﻣﺨﺘﻠﻒ و ﺗﻮاﻟﯽﯾﺎﺑﯽ ﺟﺎﯾﮕﺎه ﻣﻮردﻧﻈﺮ اﺳﺘﻔﺎده ﺷﺪ. ﻧﺘﺎﯾﺞ اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﻣﻨﺠﺮ ﺑﻪ ﺷﻨﺎﺳﺎﯾﯽ 4 اﻟﮕﻮي ﻣﺨﺘﻠﻒ در اﮔﺰون 4 ژن ﻫﻮرﻣﻮن رﺷﺪ ﮔﺮدﯾﺪ ﮐﻪ ﺑﺎ ﺑﺮرﺳﯽ ﺗﻮاﻟﯽﻫﺎي ﺣﺎﺻﻞ از اﻟﮕﻮﻫﺎي ﻣﺨﺘﻠﻒ ﻣﻨﺠﺮ ﺑﻪ ﺷﻨﺎﺳﺎﯾﯽ ﭘﻨﺞ ﺟﻬﺶ ﺷﺪ ﮐﻪ اﯾﺠﺎدﮐﻨﻨﺪه 4 ﻫﺎﭘﻠﻮﺗﯿﭗ III ،II ،I و IV ﺑﺎ ﻓﺮاواﻧﯽ ﺑﻪﺗﺮﺗﯿﺐ 0/24، 0/46، 0/17 و 0/13 ﺑﻮد. آﻧﺎﻟﯿﺰ ارﺗﺒﺎط اﺛﺮ ﻫﺎﭘﻠﻮﺗﯿﭗﻫﺎي ﺷﻨﺎﺳﺎﯾﯽ ﺷﺪه ﺑﺎ ﺻﻔﺎت ﺗﻮﻟﯿﺪي ﻧﺸﺎن داد ﮐﻪ ﻫﺎﭘﻠﻮﺗﯿﭗﻫﺎي ﻣﺨﺘﻠﻒ ﺗﺄﺛﯿﺮ ﻣﻌﻨﯽداري ﺑﺮ ﺻﻔﺎت ﻣﯿﺰان ﺗﻮﻟﯿﺪ ﺷﯿﺮ، درﺻﺪ ﭼﺮﺑﯽ، درﺻﺪ ﭘﺮوﺗﺌﯿﻦ داﺷﺘﻪ )p<0.05( درﺣﺎﻟﯽﮐﻪ ﺗﺄﺛﯿﺮي ﺑﺮ روي ﺻﻔﺎت درﺻﺪ ﻻﮐﺘﻮز و ﻣﯿﺰان ﻣﻮاد ﺟﺎﻣﺪ ﺷﯿﺮ ﻧﺪاﺷﺖ. ﻫﻢﭼﻨﯿﻦ ﺗﻨﻮع ﻧﻮﮐﻠﺌﻮﺗﯿﺪي و ﻫﺎﭘﻠﻮﺗﯿﭙﯽ ﺷﻨﺎﺳﺎﯾﯽ ﺷﺪه ﺑﺎﻋﺚ اﯾﺠﺎد وارﯾﺎﻧﺲ در ﺻﻔﺖ ﭼﻨﺪﻗﻠﻮزاﯾﯽ ﻣﯽﺷﻮد ﺑﻪﻃﻮريﮐﻪ ﺣﯿﻮاﻧﺎت ﺑﺎ ﻫﺎﭘﻠﻮﺗﯿﭗ II ﺑﯿﺶﺗﺮﯾﻦ ﻣﯿﺰان ﭼﻨﺪﻗﻠﻮزاﯾﯽ )2/159( و ﻫﺎﭘﻠﻮﺗﯿﭗ IV ﮐﻢﺗﺮﯾﻦ ﻣﯿﺰان ﭼﻨﺪﻗﻠﻮزاﯾﯽ )1/40( را داﺷﺘﻨﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن ﻣﯽدﻫﺪ ﮐﻪ ﻫﺎﭘﻠﻮﺗﯿﭗ II ﺑﺮاي ﺻﻔﺖ ﭼﻨﺪﻗﻠﻮزاﯾﯽ و ﻫﺎﭘﻠﻮﺗﯿﭗﻫﺎي II ،I و IV ﺑﺮاي ﺻﻔﺎت ﺗﻮﻟﯿﺪ ﺷﯿﺮ و ﺗﺮﮐﯿﺒﺎت آن ﻣﯽﺗﻮاﻧﺪ ﯾﮏ ﻧﺸﺎﻧﮕﺮ ژﻧﺘﯿﮑﯽ ﻣﻨﺎﺳﺐ ﺑﻪﺷﻤﺎر رود.

This study was performed to investigate genetic variation of growth hormone gene and association analysis on important traits in Khalkhali dairy goats. PCR-SSCP method and Sanger sequencing were used for genotyping. In total, four different Polymorphic SSCP patterns were detected in the amplified region that leads to identify 5 mutations in exon 4 of growth hormone gene. In total we observed four haplotypes that were related to the polymorphic patterns. The frequency of haplotypes I, II, III and IV were 0.24, 0.46, 0.17 and 0.13, respectively. The results showed significant effect of haplotypes on milk yield, milk fat and protein percentage of Khalkhali goat (p<0.05), but there is no association with milk lactose and solid matter percentage (p<0.05). Variations observed in this study made effective difference in litter size. Animals with haplotype II showed the most litter size with 2.159 kids in average and haplotype IV has the lowest with 1.40 kids per animal. The results of this study indicated that haplotype II (for litter size) and haplotypes IV, II, I (for milk yield and milk composition) could be considered as a marker in marker-assisted selection for improving the traits in khalkhali goats.