A walk though vertebrate and invertebrate protamines

Abstract
An updated comparative analysis of protamines and their corresponding genes is presented, including representative organisms from each of the vertebrate classes and one invertebrate (squid, Loligo opalescens). Special emphasis is placed on the implications for sperm chromatin organization and the evolutionary significance. The review is based on some of the most recent publications in the field and builds upon previously published reviews on this topic.