Characteristics of a Novel Tyrosinase Gene Involved in the Formation of Shell Color in Hard Clam Mer

• 作 者: YAO Hanhan CUI Baoyue LI Xiaoying LIN Zhihua DONG Yinghui
• 机 构: Zhejiang Key Laboratory of Aquatic Germplasm Resources,College of Biological & Environmental Science
• 出 处: 中国海洋大学学报（英文版）
• 发表日期: 2020年1期
• 关键词: Meretrix meretrix shell color tyrosinase melanin

Hard clam (Meretrix meretrix) has a rich shell color variation among individuals from light yellow to bluish gray,brown red,and black,which may associating with melanin.Tyrosinase (Tyr) is a key rate-limiting enzyme for the biosynthesis of melanin,which affects the dark color of animal skin,hair,fur,scales and feathers.Here,we isolated and characterized the full-length cDNA sequence of M.meretrix tyrosinase gene (MmTyr) which encodes a protein with 689 amino acids.Sequence characteristics and phylogenetic analysis showed that there are a variety of Tyr genes in mollusks,which can be divided into dif-ferent categories.The abundance of MmTyr transcript was detected in six tissues including mantle,adductor muscle,digestive gland,foot,gill and siphon of adult M.meretrix with qRT-PCR.The results showed a higher expression specifically in the mantle,digestive gland and siphon,which was consistent with the phenotypic color difference.In the embryos and larvae at different de-velopmental stages,high expression was found in the trochophore larvae and juvenile clams.Among three M.meretrix strains with different shell colors,the expression level of MmTyr and total melanin content in the mantle edge both showed significant differ-ences,suggesting that MmTyr is involved in the formation of shell color.The results obtained in this study will improve our under-standing of molluscan tyrosinase gene function and molecular mechanism of shell color patt determination.