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Abstract Background Despite the growing interest in the female side of copulatory interactions, the roles played by differential expression and alternative splicing mechanisms of pre-RNA on tissues outside of the reproductive tract have remained largely unknown. Here we addressed these questions in the context of con- vs heterospecific matings between Drosophila mojavensis and its sister species, D. arizonae. We analyzed transcriptional responses in female heads using an integrated investigation of genome-wide patterns of gene expression, including differential expression (DE), alternative splicing (AS) and intron retention (IR). Results Our results indicated that early transcriptional responses were largely congruent between con- and heterospecific matings but are substantially perturbed over time. Conspecific matings induced functional pathways related to amino acid balance previously associated with the brain’s physiology and female postmating behavior. Heterospecific matings often failed to activate regulation of some of these genes and induced expression of additional genes when compared with those of conspecifically-mated females. These mechanisms showed functional specializations with DE genes mostly linked to pathways of proteolysis and nutrient homeostasis, while AS genes were more related to photoreception and muscle assembly pathways. IR seems to play a more general role in DE regulation during the female postmating response. Conclusions We provide evidence showing that AS genes substantially perturbed by heterospecific matings in female heads evolve at slower evolutionary rates than the genome background. However, DE genes evolve at evolutionary rates similar, or even higher, than those of male reproductive genes, which highlights their potential role in sexual selection and the evolution of reproductive barriers.

Background: Despite the growing interest in the female side of copulatory interactions, the roles played by differential expression and alternative splicing mechanisms of pre-RNA on tissues outside of the reproductive tract have remained largely unknown. Here we addressed these questions in the context of con- vs heterospecific matings between Drosophila mojavensis and its sister species, D. arizonae. We analyzed transcriptional responses in female heads using an integrated investigation of genome-wide patterns of gene expression, including differential expression (DE), alternative splicing (AS) and intron retention (IR). Results: Our results indicated that early transcriptional responses were largely congruent between con- and heterospecific matings but are substantially perturbed over time. Conspecific matings induced functional pathways related to amino acid balance previously associated with the brain's physiology and female postmating behavior. Heterospecific matings often failed to activate regulation of some of these genes and induced expression of additional genes when compared with those of conspecifically-mated females. These mechanisms showed functional specializations with DE genes mostly linked to pathways of proteolysis and nutrient homeostasis, while AS genes were more related to photoreception and muscle assembly pathways. IR seems to play a more general role in DE regulation during the female postmating response. Conclusions: We provide evidence showing that AS genes substantially perturbed by heterospecific matings in female heads evolve at slower evolutionary rates than the genome background. However, DE genes evolve at evolutionary rates similar, or even higher, than those of male reproductive genes, which highlights their potential role in sexual selection and the evolution of reproductive barriers. [ABSTRACT FROM AUTHOR]

Chemosensory proteins (CSPs) are important for insect chemoreception, which bind, solubilize and transport hydrophobic chemical molecules from external environment to dendrite membrane of chemosensory neurons. Moreover, CSPs are also involved in non-sensory physiological activities. The peach fruit borers Carposina sasakii Matsumura (Lepidoptera: Carposinidae) seriously damage fruit trees and their chemoreception mainly occurs in the adult stage. We identified 10 putative CSPs (Csas CSP1 ~ Csas CSP10) from head transcriptomes of C. sasakii adult males and females, all of which are classic CSPs that have 4 conserved cysteines with a spacing pattern C 1 –X 6 –C 2 –X 17 – 18 –C 3 –X 2 –C 4. Their phylogenetic characteristics were also described. An analysis using fluorescence quantitative PCR showed Csas CSP2 has the highest level of expression in the heads, so it is more likely to be involved in C. sasakii chemoreception than the other C. sasakii CSPs. Csas CSP1, Csas CSP3, Csas CSP4, Csas CSP6, Csas CSP7 and Csas CSP8 are expressed dominantly in the wings; Csas CSP5 and Csas CSP10 have the highest expression level in the thoraxes; Csas CSP9 is dominantly and equally expressed in the thoraxes and abdomens. This study contributes to understanding physiological functions of C. sasakii CSPs and chemosensory mechanism at C. sasakii molecular level. Relative expressions of putative C. sasakii CSPs (Csas CSP1 ~ Csas CSP10) in C. sasakii heads, wings, thoraxes and abdomens. Gene expressions in different tissues are normalized, relative to that in heads. Data are displayed as the mean of three replicates with standard deviation (the bar). Significant differences in the relative expressions between different tissues are indicated by different letters at the bars (P < 0.05; LSD test). [Display omitted] • 10 putative chemosensory proteins are identified from Carposina sasakii. • Phylogenetic characteristics of these chemosensory proteins are shown. • Tissue- and sex-specific expressions of these chemosensory proteins were studied. [ABSTRACT FROM AUTHOR]