Gene Expression Rhythms in the Mussel Mytilus galloprovincialis (Lam.) across an Annual Cycle

Abstract

Seasonal environmental changes may affect the physiology of Mytilus galloprovincialis (Lam.), an intertidal filter-feeder bivalve occurring commonly in Mediterranean and Atlantic coastal areas. We investigated seasonal variations in relative transcript abundance of the digestive gland and the mantle (gonads) of males and females. To identify gene expression trends – in terms of relative mRNA abundance- we used a medium-density cDNA microarray (1.7 K probes) in dual-color competitive hybridization analyses. Hierarchical clustering of digestive gland microarray data showed two main branches, distinguishing profiles associated with the “hot” months (May–August) from the other months. Genes involved in chitin metabolism, associated with mussel nutrition and digestion showed higher mRNA levels during summer. Moreover, we found different gene transcriptomic patterns in the digestive glands of males when compared to females, during the four stages of mussel gonadal development. Microarray data from gonadal transcripts also displayed clear patterns during the different developmental phases respect to the resting period (stage I) with peak relative mRNA abundance at the ripe phase (stage III) for both sexes. These data showed a clear temporal pattern in transcriptomic profiles of mussels sampled over an annual cycle. Physiological response to thermal variation, food availability, and reproductive status across months may contribute to variation in relative mRNA abundance.

The environmentally tuned transcriptomes ofMytilusmussels

“…These environmental shifts disrupt molecular structures and perturb cellular processes (Kültz, 2005) and Mytilus spp. have adapted to cope with these changes via mechanisms that preserve cellular homeostasis (Banni et al, 2011;Gilby et al, 1997;Hofmann and Somero, 1995). However, each species is adapted to cope with the range of conditions that they most often encounter in their native environments.…”

Physiology and Biogeography: The Response of European Mussels (Mytilusspp.) to Climate Change*

“…Much of this distribution was reported in Hilbish et al (2012), who sampled 97 locations along the Atlantic coast of Spain and France. However, we developed an even more extensive range database by collating data from several studies (Lionetto et al 2003, Gosling et al 2008, Pisanelli et al 2009, Banni et al 2011, Kijewski et al 2011, Hilbish et al 2012. data, Appendix A) as well as sampling in certain regions that were missing recent data (particularly the United Kingdom).…”

Changes of the mRNA Expression Pattern of Zn Transporters: a Probable Mechanism for Cadmium Retention and Zinc Redistribution in the Suckling Rat Tissues

“…The RNA purity was verified by the optical density (OD) 260 /OD 280 absorption ratio (>1.8). A total amount of 1.5-2 μg of total RNA was reversetranscribed in a 20-μl reaction mixture using random hexamer primers (Roche) and 200 U of M-MuLV H-RT (Fermentas, Vilnius, Lithuania), 0.5 mM dNTPs (Roche), 19 M-MulV RT buffer as described in Banni et al [23]. Briefly, the RNA was denatured by heating for 5 min at 70°C, cooled on ice, and incubated with reverse transcriptase reaction mixture.…”

“…The mRNA abundances of the genes encoding ZIP3, ZIP4, ZIP8, ZnT1, ZnT2, and ZnT4 were evaluated in multiplex Taqman assays according to Banni et al [23]. Probes and primer pairs (Table 1) were designed using Beacon Designer v3.0 (Premier Biosoft International, Inc.).…”