Molecular characterization and evolution of a gene family encoding male-specific reproductive proteins in the African malaria vector <it<Anopheles gambiae</it<

<p<Abstract</p< <p<Background</p< <p<During copulation, the major Afro-tropical malaria vector <it<Anopheles gambiae </it<s.s. transfers male accessory gland (MAG) proteins to females as a solid mass (i.e. the "mating plug"). These proteins are pos...
Ausführliche Beschreibung

<p<Abstract</p< <p<Background</p< <p<During copulation, the major Afro-tropical malaria vector <it<Anopheles gambiae </it<s.s. transfers male accessory gland (MAG) proteins to females as a solid mass (i.e. the "mating plug"). These proteins are postulated to function as important modulators of female post-mating responses. To understand the role of selective forces underlying the evolution of these proteins in the <it<A. gambiae </it<complex, we carried out an evolutionary analysis of gene sequence and expression divergence on a pair of paralog genes called <it<AgAcp34A-1 </it<and <it<AgAcp34A-2</it<. These encode MAG-specific proteins which, based on homology with <it<Drosophila</it<, have been hypothesized to play a role in sperm viability and function.</p< <p<Results</p< <p<Genetic analysis of 6 species of the <it<A. gambiae </it<complex revealed the existence of a third paralog (68-78% of identity), that we named <it<AgAcp34A-3</it<. FISH assays showed that this gene maps in the same division (34A) of chromosome-3R as the other two paralogs. In particular, immuno-fluorescence assays targeting the C-terminals of <it<AgAcp34A-2 </it<and <it<AgAcp34A-3 </it<revealed that these two proteins are localized in the posterior part of the MAG and concentrated at the apical portion of the mating plug. When transferred to females, this part of the plug lies in proximity to the duct connecting the spermatheca to the uterus, suggesting a potential role for these proteins in regulating sperm motility. <it<AgAcp34A-3 </it<is more polymorphic than the other two paralogs, possibly because of relaxation of purifying selection. Since both unequal crossing-over and gene conversion likely homogenized the members of this gene family, the interpretation of the evolutionary patterns is not straightforward. Although several haplotypes of the three paralogs are shared by most <it<A. gambiae </it<s.l. species, some fixed species-specific replacements (mainly placed in the N- and C-terminal portions of the secreted peptides) were also observed, suggesting some lineage-specific adaptation.</p< <p<Conclusions</p< <p<Progress in understanding the signaling cascade in the <it<A. gambiae </it<reproductive pathway will elucidate the interaction of this MAG-specific protein family with their female counterparts. This knowledge will allow a better evaluation of the relative importance of genes involved in the reproductive isolation and fertility of <it<A. gambiae </it<species and could help the interpretation of the observed evolutionary patterns.</p< Ausführliche Beschreibung

Autor*in:	Sharakhov Igor V [verfasserIn] Masiga Daniel [verfasserIn] Morlais Isabelle [verfasserIn] George Phillip [verfasserIn] Serrao Aurelio [verfasserIn] Calzetta Maria [verfasserIn] Tammaro Federica [verfasserIn] Baldini Francesco [verfasserIn] Mancini Emiliano [verfasserIn] Rogers David W [verfasserIn] Catteruccia Flaminia [verfasserIn] della Torre Alessandra [verfasserIn]

Format:	E-Artikel
Sprache:	Englisch

Erschienen:	2011

Übergeordnetes Werk:	In: BMC Evolutionary Biology - BMC, 2003, 11(2011), 1, p 292
Übergeordnetes Werk:	volume:11 ; year:2011 ; number:1, p 292

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DOI / URN:	10.1186/1471-2148-11-292

Katalog-ID:	DOAJ06149691X