Production of different phenotypes from the same genotype in the same environment by developmental variation

Abstract

SUMMARY The phenotype of an organism is determined by the genes, the environment and stochastic developmental events. Although recognized as a basic biological principle influencing life history, susceptibility to diseases, and probably evolution, developmental variation (DV) has been only poorly investigated due to the lack of a suitable model organism. This obstacle could be overcome by using the recently detected, robust and highly fecund parthenogenetic marbled crayfish as an experimental animal. Batch-mates of this clonal crayfish, which were shown to be isogenic by analysis of nuclear microsatellite loci,exhibited surprisingly broad ranges of variation in coloration, growth,life-span, reproduction, behaviour and number of sense organs, even when reared under identical conditions. Maximal variation was observed for the marmorated coloration, the pattern of which was unique in each of the several hundred individuals examined. Variation among identically raised batch-mates was also found with respect to fluctuating asymmetry, a traditional indicator of the epigenetic part of the phenotype, and global DNA methylation, an overall molecular marker of an animal's epigenetic state. Developmental variation was produced in all life stages, probably by reaction–diffusion-like patterning mechanisms in early development and non-linear, self-reinforcing circuitries involving behaviour and metabolism in later stages. Our data indicate that, despite being raised in the same environment, individual genotypes can map to numerous phenotypes viaDV, thus generating variability among clone-mates and individuality in a parthenogenetic species. Our results further show that DV, an apparently ubiquitous phenomenon in animals and plants, can introduce components of randomness into life histories, modifying individual fitness and population dynamics. Possible perspectives of DV for evolutionary biology are discussed.

Constraints and flexibility in mammalian social behaviour: introduction and synthesis

“…However, there is also variation in the behavioural outcomes of development among otherwise rather similar individuals, such as littermates, that are brought about by differential accommodation to the disruptions of normal development. The strength of such developmental variability has been revealed by a remarkable study of clonal crayfish raised under identical environmental conditions [137], but it remains poorly studied among mammals. Epigenetic modifications of genetic information can also result in modulation of offspring social behaviour in response to social or ecological stimuli during early development [138,139], highlighting the fact that genetic and developmental mechanisms are inseparable and may often be closely linked to social and ecological ones.…”

Different aspects of reproduction strategies in crayfish: A review

“…The phenotype of an organism is determined by the genes, the environment and by stochastic developmental events (Vogt et al, 2008). Vogt et al (2008) stated that, even in the same environment, individual genotypes can produce different phenotypes because of developmental variation, resulted in generating variability among clone-mates and individuality in a parthenogenetic species.…”

“…Vogt et al (2008) stated that, even in the same environment, individual genotypes can produce different phenotypes because of developmental variation, resulted in generating variability among clone-mates and individuality in a parthenogenetic species. This developmental variation, an apparently ubiquitous phenomenon in living beings, can introduce elements of randomness into life histories, altering individual fitness and subsequently population dynamics.…”

Engrailed-like immunoreactivity in the embryonic ventral nerve cord of the Marbled Crayfish (Marmorkrebs)

“…Its closest relatives seem to belong to the genus Procambarus (Scholtz et al 2003). Unpublished molecular analyses of its mitochondrial genome suggest it to be a parthenogentic strain of the North American cambarid Procambarus alleni (Keith Crandall, unpublished data as cited in Vogt et al 2008). This organism is an outstanding crustacean because it provides the first example for parthenogenesis within the decapod crustaceans (Scholtz et al 2003;Seitz et al 2005).…”

“…This organism is an outstanding crustacean because it provides the first example for parthenogenesis within the decapod crustaceans (Scholtz et al 2003;Seitz et al 2005). Most recently, it has been shown that the Marbled Crayfish reproduces by apomictic parthenogenesis, the most common asexual reproductive mode among invertebrates (Martin et al 2007;Vogt et al 2008). By apomictic propagation, the offspring conserve the original genetic information and, thus, are identical clones of the mother (Martin et al 2007).…”