title: Seasonal photoperiodism regulates the expression of cuticular and signalling protein genes in the pea aphid.
abstract: Seasonal photoperiodism in aphids is responsible for the spectacular switch from asexual to sexual reproduction. However, little is known on the molecular and physiological mechanisms involved in reproductive mode shift through the action of day length. Earlier works showed that aphid head, but not eyes, directly perceives the photoperiodic signal through the cuticle. In order to identify genes regulating the photoperiodic response, a 3321 cDNA microarray developed for the pea aphid, Acyrthosiphon pisum was used to compare RNA populations extracted from heads of short- and long-day reared aphids. Microarray analyses revealed that 59 different transcripts were significantly regulated, among which a majority encoded cuticular proteins and several encoded proteins involved in cellular signalling or signal transduction. These results were confirmed by quantitative RT-PCR experiments on two cuticular and three signalling protein genes. Complementary experiments eliminated moulting and circadian rhythms as putative confounding effects. Quantitative RT-PCR performed at additional developmental stages demonstrated the regulation of expression of cuticular and signalling protein genes during the whole process of photoperiod shortening. This suggests that photoperiodic changes could affect cuticle structure and cell to cell communication in the head of aphids in relation with the switch of reproductive modes.
authors.affiliation: INRA, Agrocampus Rennes, UMR 1099 BiO3P (Biology of Organisms and Populations Applied to Plant Protection), F-35653 LE RHEU, France.
authors.forename: G
authors.initials: G
authors.lastname: Le Trionnaire
authors.forename: S
authors.initials: S
authors.lastname: Jaubert
authors.forename: B
authors.initials: B
authors.lastname: Sabater-Muñoz
authors.forename: A
authors.initials: A
authors.lastname: Benedetto
authors.forename: J
authors.initials: J
authors.lastname: Bonhomme
authors.forename: N
authors.initials: N
authors.lastname: Prunier-Leterme
authors.forename: D
authors.initials: D
authors.lastname: Martinez-Torres
authors.forename: J-C
authors.initials: JC
authors.lastname: Simon
authors.forename: D
authors.initials: D
authors.lastname: Tagu
mesh_terms: D000818:Animals; D001042:Aphids / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000528:radiation effects*; D006257:Head; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D017440:Photoperiod; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012621:Seasons; D015398:Signal Transduction / Q000528:radiation effects