Biochemistry And Functional Genes Analysis Of Musculature From Amphioxus (Branchiostoma Belcheri Tsingtauense)

This thesis mainly focus on the Enzyme histochemistry and TEM observation of trunk muscle from Branchiostoma belcheri tsingtauense (Bbt); isolation and recombinant expression of Bbt-myosin heavy chain isoforms; characterization and expression of Bbt-nascent-polypeptide-associated complexαsubunit.In NADH Enzyme histochemistry, two types of muscle lamella can be distinguished .The oxidative superficial muscle was stained dark blue while the glycolytic deep one was almost unstained. TEM observation confirmed the results of Enzyme histochemistry. Furthermore, it was noticed that there was clearly higher myofilaments density in superficial and intermediate lamellae than the deep one. While in mATPase histochemistry, there is no difference among different lamellae. Maybe the lamellae were inactive or deactivation under those pHs, or additional metal ions being different from muscle fiber (lamellae) of other species should be added for this display.Three isoforms of myosin heavy chain fragments, two of which were the first time reported, were isolated. They belonged to class II myosin and had high identities with different kinds of muscle myosin of vertebrates and invertebrates. One of them was recombinant expressed in E.coli. A soluble fusion protein which would be a good resource for anti-Bbt-MyHC antibodies preparation was obtained.The full length cDNA of the nascent-polypeptide-associated complexαsubunit gene was cloned and it was found to be expressed in all of the checked stages and tissues. The genomic sequence of 5'end was obtained and analyzed; however, it seemed that there was no ortholog of the muscle-specific NAC in amphioxus.