Expression Analysis Of Blin-Binding Protein 3 (ApBBP3) And Apolipoprotein D (ApapoD) In Antheraea Pernyi

The green color of the body wall of the larvae in Lepidoptera is believed to be the product of the combination of yellow and blue pigment.Most of the yellow pigment is carotenoids,and the blue pigment is biliverdin.After the combination of pigment and binding protein,the pigment is deposited on tissues and organs to show the corresponding color.Bilirubin binding protein(BBP),belongs to apolipoprotein family,can bind with blue pigment.Apolipoprotein D(apo D)is a kind of glycoprotein that binds to a variety of small hydrophobic molecules,including bilirubin,progesterone and cholesterol.The body wall of wild Antheraea pernyi larvae appears yellow-green to protective.Their body colors show a high degree of diversity,such as white,blue,red and yellow,etc.with the long-term evolution and artificial selection.The color of China oak silkworm is the characteristic of breeding in practice.However,there is no report about the color related genes were cloned in Antheraea pernyi.We cloned the biliverdin binding protein 3(ApBBP3)and apolipoprotein D(Apapo D)gene of Antheraea pernyi,carried on the bioinformatics analysis,and detected the level of m RNA expression in different tissues and organs in green and yellow larvae.In order to find the key genes about green and yellow A.pernyi larvae,meanwhile,we will found the reason that the molecular mechanism of A.pernyi larva body color differentiation.In addition,this study on body color and molecular of Chinese oak silkworm is also instructive to the breeding.The main results are as follows:1.ApBBP3 encodes 203 amino acids with a molecular weight of 50.95 k Da and an isoelectric point of 5.16.The amino acid sequence alignment showed that the similarity between ApBBP3(Gene Bank ID,AFH68246)was 100%.ApBBP3 contains a signal peptide at 1-16 position,but there was no transmembrane region in it.Apapo D encodes 207 amino acids with a molecular weight of 51.11 k Da and an isoelectric point of 5.23.Amino acid sequence alignment showed that Apapo D was 69% similar to apolipoprotein D(Gene Bank ID,XP004923379)of silkworm.Apapo D contains a signal peptide at 1-16 position,and there was a transmembrane region in it.2.Both BBP and apo D belong to the apolipoprotein family.The molecular evolution tree constructed showed that BBP and ApBBP3 are clustered together,and apolipoprotein and Apapo D are clustered together,indicating that these related proteins come from a common ancestor.Apolipoprotein was divided into two parts,indicating that the apolipoprotein sequence was further divided into invertebrates and vertebrates subgroups.3.The ApBBP3 were expressed in all tissues and organs by the q RT-PCR method.There were no significant differences of the relative expression level between yellow and greenlarva in hemolymph and silk glands.There were differences of relative expression level between yellow and green larva in the fat body and the midgut.There were significant differences between green and yellow larvae in integument.The Apapo D was expressed in all tissues and organs by the q RT-PCR method except in silk gland.There were no difference of relative expression levels between green and yellow larva in haemolymph,midgut,fat body and integument.The q RT-PCR results indicating that ApBBP3 may play a role in the process of body color differentiation between green and yellow Antheraea pernyi larvae,while Apapo D may not have relevant functions.