Paternal contribution to development: Sperm genetic damage and repair in fish

Abstract

In this review we provide an overview of the components of the spermatozoa playing an important role in reproductive success beyond fertilization, showing the relationship between the integrity of the diverse elements and the development of a healthy offspring. The present knowledge about fish sperm chromatin organization, epigenetic modifications of DNA and histones and sperm-borne RNAs, essential in controlling embryo development, is summarized, pointing out the possibility of using specific genes or transcripts as biomarkers of sperm quality. Data about commercial species are reported when available and more detailed information about zebrafish sperm is presented.Considering the implications that the integrity of sperm genome and epigenome has on the preservation of a proper genotype and phenotype in the progeny, the methods applied for the study of chromatin damage and for the study of transcriptome are described. Moreover we discuss some injuring agents affecting paternal information, from the presence of contaminants in the aquatic environment, to the reproductive *Manuscript Click here to download Manuscript: Herrez et al revised aquaculture.docx Click here to view linked References practices applied in fish farming. The consequences of fertilizing with damaged spermatozoa, as well as the zygotic ability to repair damage are also reviewed.

Potential biomarkers of DNA quality in cryopreserved fish sperm: impact on gene expression and embryonic development

“…This method, used in studies involving the cryopreservation of human sperm, has been applied to detect lesions in genes that are key to the fertilization and early development of human embryos. Additionally, lesions have been quantified in specific genes in the primordial germ cells (PGCs) of zebrafish (Cart on-Garc ıa et al 2013; Gonz alez-Rojo et al 2014;Herr aez et al 2017).…”

“…It has been used to increase the longevity of spermatozoa for periods extending to years (Betsy & Kumar ); however, it can cause extensive cellular and molecular damage, not yet studied in full, leading to a reduction in sperm quality and an increased rate of malformed embryos (Herráez et al . ). It has been shown that cryopreservation alters structural and physiological components of cells, specifically affecting plasma membrane integrity, mitochondrial membrane potential (ΔΨm) and enzyme activity; while production of free radicals (ROS) increases and ATP concentrations are disrupted (Figueroa et al .…”

“…; Herráez et al . ; Fernández‐Díez & Herráez ). Studies in sheep and human gametes and embryos have shown that both DNA integrity and gene expression are negatively affected by cryopreservation.…”

“…Furthermore, some studies have shown differing susceptibilities of sperm nuclear genes to cryodamage (Cart on-Garc ıa et al 2013; Gonz alez-Rojo et al 2014), affecting both nuclear DNA (nDNA) and mitochondrial DNA (mtDNA). These negative effects do not always decrease sperm functionality and fertilization capacity; however, they may affect cellular and molecular processes post-fertilization and generate defective embryos (P erez-Cerezales et al 2011;Herr aez et al 2017;Fern andez-D ıez & Herr aez 2018). Studies in sheep and human gametes and embryos have shown that both DNA integrity and gene expression are negatively affected by cryopreservation.…”

Improvement of techniques for sperm evaluation and cryobanking in European eel.

“…Several studies suggested that the drastic changes occurring during freezing and thawing may affect the DNA of cryopreserved spermatozoa (Labbé et al, 2017;Pérez-Cerezales et al, 2010). Furthermore, the use of methylated cryoprotectants is known to induce the production of reactive oxygen species (ROS) that can cause several damages, such as cytosine methylation in fish spermatozoa DNA (Kawai et al, 2010), which is one of the principal epigenetic mechanisms (Bird, 2002), and have been suggested to be a good indicator for sperm quality (Herráez et al, 2017), affecting consequently the success of a cryopreservation protocol. In this comparative study, Herranz-Jusdado et al (2019a) showed that the protocol using methanol, initially developed by the Hungarian group (Müller et al, 2012;Szabó et al, 2005), was better in terms of higher spermatozoa viability and motility than the protocol with DMSO developed by the Spanish group (Asturiano et al, 2016;Peñaranda et al, 2009).…”