Epigenetic Maternal Effects on Endogenous Rhythms in Precocial Birds

Abstract

Development involves interactions between genetic and environmental influences. Vertebrate mothers are generally the first individuals to encounter and interact with young animals. Thus, their role is primordial during ontogeny. The present study evaluated non-genomic effects of mothers on the development of rhythms of precocial Japanese quail (Coturnix c. japonica). First, we investigated the influence of mothering on the ontogeny of endogenous rhythms of young. We compared circadian and ultradian rhythms of feeding activity of quail reared with or without adoptive mothers. More brooded than non-brooded quail presented a circadian and/or an ultradian rhythm. Thus, the presence of the mother during the normal brooding period favors, in the long term, expression of rhythms in the young. Second, we investigated the influence of rhythmic phenotype of the mother on the development of endogenous rhythms of young by comparing quail brooded by circadian-rhythmic adoptive mothers (R) to quail brooded by circadian-arrhythmic adoptive mothers (A). More R-brooded than A-brooded quail expressed circadian rhythmicity, and circadian rhythm clarities were greater in R-brooded than A-brooded quail. Ultradian rhythmicity did not differ between R- and A-brooded quail, nor between R and A adoptive mothers. Thus, the rhythmic phenotypes of quail mothers influence the rhythmic phenotypes of their young. Our results demonstrate that mothers of precocial birds influence epigenetically the ontogeny of endogenous rhythms of the young they raise.

Seasonal postembryonic maturation of the diurnal rhythm of serotonin in the chicken pineal gland

“…Similar results have been described in migratory birds (Gwinner, 2003), what we recently discussed in detail in the previous publication (Piesiewicz et al, 2012b). The mechanisms underlying ''photoperiodic memory'' are still unknown, but epigenetic factors, such as maternal behavior, may influence the rhythmic phenotype of the offspring (Formanek et al, 2009;Janczak et al, 2007;Piesiewicz et al, 2012b). Moreover, it was showed that in chickens unpredictable food access caused seemingly adaptive responses in feeding behavior and this changed behavior was then transmitted to the offspring by epigenetic mechanisms (Natt et al, 2009).…”

Clocks for the city: circadian differences between forest and city songbirds

“…In addition, epigenetic and specifically maternal effects can alter endogenous rhythmicity. For example, in quails the circadian phenotype of the mothers can predict that of their young [36]. Finally, as already mentioned above, after-effects of previous environmental exposure may affect circadian period length t [28], for example, depending on the amplitude and length of the photoperiod an animal experiences [37][38][39][40].…”

Rhythmic Birds Show a Better Social Integration than Arrhythmic Birds

“…When the quail were 3 wks old, they were caged individually in soundproof rooms in order to record their endogenous feeding rhythmicity under DD. The procedure is described in Guyomarc'h and Guyomarc'h (1994) and rhythms analysis in Formanek et al (2009). We then selected circadian rhythmic (R) and circadian arrhythmic (A) individuals for reproduction.…”

“…Japanese quail maintained in constant darkness (DD) display freerunning feeding activity rhythms with a large interindividual variability of rhythmicity level; some quail express a robust circadian and/or ultradian rhythm, whereas others express a noisy rhythm, or no rhythm at all (Formanek et al, 2009;Guyomarc'h et al, 1998;Lumineau et al, 2001). Performing a divergent selection based on the level of circadian rhythmicity in DD, we obtained two distinct lines of quail.…”

“…In addition, groups of R-chicks are better synchronized behaviorally than are groups of A-chicks (Lumineau et al, 2001). Finally, the mother that leads the chicks during the early age can modify the rhythm clarity of the offspring after dispersal (Formanek et al, 2009).…”