Sex-Specific Regulation of AMP-Activated Protein Kinase (AMPK) in the Pacific Oyster Crassostrea gigas1

Abstract

The hermaphrodite Pacific oyster Crassostrea gigas displays a high energy allocation to reproduction. We studied the expression of AMP-activated protein kinase (AMPK) during gametogenesis in the gonad and characterized the mRNA sequences of the AMPK subunits: the AMPK alpha mRNA sequence was previously characterized; we identified AMPK beta, AMPK gamma, and mRNAs of putative AMPK-related targets following bioinformatics mining on existing genomic resources. We analyzed the mRNA expression of the AMPK alpha, beta, and gamma subunits in the gonads of male and female oysters through a reproductive cycle, and we quantified the mRNA expression of genes belonging to fatty acid and glucose metabolism. AMPK alpha mRNA levels were more abundant in males at the first stage of gametogenesis, when mitotic activity and the differentiation of germinal cells occur, and were always more abundant in males than in females. Some targets of fatty acid and glucose metabolism appeared to be correlated with the expression of AMPK subunits at the mRNA level. We then analyzed the sex-specific AMPK activity by measuring the phosphorylation of the catalytic AMPK alpha protein and its expression at the protein level. Both the amount of AMPK alpha protein and threonine 172 phosphorylation appeared to be almost totally inhibited in mature female gonads at stage 3, at the time when accumulation of reserves in oocytes was promoted, while it remained at a high level in mature spermatozoa. Its activation might play a sex-dependent role in the management of energy during gametogenesis in oyster.

Conjugated Linoleic Acid Regulates Body Composition and Locomotor Activity in a Sex‐Dependent Manner in Drosophila melanogaster

“…However, the current results showed that CLA induced AMPKα activation only in female flies. This type of sex‐specific regulation of AMPKα was previously observed in other organisms with differing energy abundance and utilization between sexes (Guevelou et al, ; Zawada et al, ). It is also possible that the increase of locomotor activity by CLA in males may be associated with carbohydrate metabolism (decrease in akh ) and/or courtship behavior, independent of AMPKα.…”

Effects of hydrodynamic factors on Pecten maximus larval development

“…Samples were weighted and homogenized in a Tris‐HCl buffer (pH 7.4) as described in Guévélou et al. (). Total protein extraction was performed using an Ultra‐Turax (Kinematica Kriens‐Lu) in an ice‐bath followed by a centrifugation at 15000 g during 20 min at 4°C.…”

Impact of 5'-amp-activated Protein Kinase on Male Gonad and Spermatozoa Functions

“…Relationships between metabolism and fertility are well established, particularly in the female. Recent discoveries show that AMPK is also present in male gonad and spermatozoa in different species [Caenorhabditis elegans (Lee et al, 2008), oyster (Guevelou et al, 2013), chicken (Nguyen et al, 2014), boar (Hurtado de Llera et al, 2012, 2013), mouse (Tanwar et al, 2012; Tartarin et al, 2012), stallion (Cordova et al, 2014), and human Calle-Guisado et al, 2016; Shabani Nashtaei et al, 2016]. It is these roles in male gonad and spermatozoa that I will now describe.…”

“…The links between differences in subcellular localization of AMPK and spermatozoa biological characteristics of different species, however, have not yet been defined. In invertebrates, AMPK has also been highlighted in 2013 in oyster's male and female germ cells, where it is involved in the glucose and fatty acids metabolism (Guevelou et al, 2013). …”