| Summary: | 碩士 === 東海大學 === 畜產學系 === 90 === The goal of this study was to investigate the genes expressed during Tsaiya duck eggshell calcification / formation. We focused on the following three genes : the lysyl oxidase gene encoding a polypeptide that is important during inner and outer-membranes formation, the calbindin D28K gene encoding a product that transports calcium to the eggshell gland and the 5-A-1 gene, a novel gene amplified by DDRT-PCR from eggshell gland. Three PCR products were obtained from Tsaiya duck eggshell gland and these sequences were subsequently analyzed. The sequence of PCR products corresponding to the lysyl oxidase and calbindin D28K genes are very similar to these of chick, howrver, no match was found for the sequence 5-A-1 gene. Additionally, results from RT-PCR analysis indicated that the maximal levels of gene expression for lysyl oxidase, calbindin D28K, and 5-A-1 during different oviposition stages were found at 0, 18 and 6 hr immediately after oviposition, respectively. To investigate the involvement of these genes in eggshell quality, we examined the expression of these genes in eggshell glands of Tasiya ducks with strong and weak eggshell strength. The results showed that the expression of these 3 genes were higher in strong eggshell- strength Tsaiya duck than in those weak eggshell- strength one.
To further analyzed the functions of calbindin D28K gene in Tsaiya duck, we analyzed DNA sequence of calbindin D28K by Omaga computer program. According to DNA sequence, we found the coding region of calbindin D28K gene in Tsaiya duck is 789 bp, and contains four calcium binding domains, one CK2 phosphorylation site, two PKC phosphorylation sites and one TYR phosphorylation site. In conclusion, the expressions of lysyl oxidase, calbindin D28K, and 5-A-1 genes were involved in eggshell formation. The DNA sequence of calbindin D28K gene containing the EF-hand structure suggests that the calcium-binding characteristic of this gene is highly relative with eggshell quality.
|
|---|
