Introduction

Abstract

Introduction

The genomic basis of evolutionary differentiation among honey bees

“…Most of the significant gene families were found to be positively selected in a single branch, although the following five were found to be positively selected in two branches: (1) muscle myosin heavy chain, which is involved in muscle contraction (Holmes 2004;Odronitz and Kollmar 2008), was under positive selection in both A. dorsata and A. florea; (2) four and a half LIM domains protein 2, involved in heart physiology and muscle formation (Johannessen et al 2006), was under positive selection in both A. dorsata and mellifera; (3) serine-rich adhesin for platelets, which plays a role in cell adhesion (Sanchez et al 2010), was positively selected in the Apis branch and in A. florea; and (4) alpha-glucosidase 2 (AmGCS2α), which is involved in glucose metabolism, and (5) one additional orthogroup of unknown function were positively selected in both the Apis branch and A. mellifera. In the three species branches, as well as the ancestral Apis branch, several positively selected genes were identified with a function in the regulation of gene expression, cell signaling, and neural processes, as well as with an association with resistance against pathogens and xenobiotics (Supplemental Tables S1, S2).…”

Comparative genomic analysis of the arthropod muscle myosin heavy chain genes allows ancestral gene reconstruction and reveals a new type of 'partially' processed pseudogene

“…35 classes of myosins have been identified to date with each class being responsible for a different function [ 12 - 14 ]. The first myosin was identified in skeletal muscle tissue over hundred years ago (for a review about the history of muscle myosin see [ 15 ]) and, since different myosins turned up, it has been referred to as conventional myosin or class-II myosin. Class-II myosins comprise the largest and most extensively studied class not only because the muscle myosin genes and muscles have been in the focus of biophysical and biochemical studies for decades and because the metazoan species are the most studied organisms but also because this class contains the most isoforms per organism [ 12 ].…”

Molecular Structure of Muscle Filaments Determined by Electron Microscopy

“…In early models of muscle, actin and myosin were thought to coexist in a set of continuous filaments, which folded up to produce shortening. This was shown to be wrong by EM/XRD, which revealed that actin and myosin were in separate, discontinuous, parallel filaments that overlapped each other (Holmes, 2004). In combination with light microscopy, EM/XRD showed that contraction occurred through a sliding of the thick past the thin filaments, without change in their lengths.…”