Evolution at Two Levels in Fire Ants: The Relationship between Patterns of Gene Expression and Protein Sequence Evolution.

Variation in protein sequence and gene expression each contribute to phenotypic diversity, and may be subject to similar selective pressures. Eusocial insects are particularly useful for investigating the evolutionary link between protein sequence and condition-dependent patterns of gene expression because gene expression plays a central role in determining differences between eusocial insect sexes and castes. We investigated the relationship between protein coding sequence evolution and gene expression patterns in the fire ants Solenopsis invicta, S. richteri, and their hybrids to gain greater insight into how selection jointly operates on gene expression and coding sequence. We found that genes with high expression variability within castes and sexes were frequently differentially expressed between castes and sexes, as well as between species and hybrids. These results indicate that genes showing high variation in expression in one context also tend to show high variation in expression in other contexts. Our analyses further revealed that variation in both intra- and interspecific gene expression was positively associated with rate of protein sequence evolution in Solenopsis. This suggests that selective constraints on a gene operate both at the level of protein sequence and at the level of gene expression regulation. Overall, our study provides one of the strongest demonstrations that selective constraints mediate both protein sequence evolution and gene expression variability across different biological contexts and timescales.

Institutes de Justinien. I. Livres I-II / nouvellement expliquées par A.-M. Du Caurroy,...

[Institutes (français). 1841]

Institutes de Justinien. II. Livres III-IV / nouvellement expliquées par A.-M. Du Caurroy,...

[Institutes (français). 1841]

Cumulative frequency-dependent selective episodes allow for rapid morph cycles and rock-paper-scissors dynamics in species with overlapping generations.

Rock-paper-scissors (RPS) dynamics, which maintain genetic polymorphisms over time through negative frequency-dependent (FD) selection, can evolve in short-lived species with no generational overlap, where they produce rapid morph frequency cycles. However, most species have overlapping generations and thus, rapid RPS dynamics are thought to require stronger FD selection, the existence of which yet needs to be proved. Here, we experimentally demonstrate that two cumulative selective episodes, FD sexual selection reinforced by FD selection on offspring survival, generate sufficiently strong selection to generate rapid morph frequency cycles in the European common lizard Zootoca vivipara, a multi-annual species with major generational overlap. These findings show that the conditions required for the evolution of RPS games are fulfilled by almost all species exhibiting genetic polymorphisms and suggest that RPS games may be responsible for the maintenance of genetic diversity in a wide range of species.

Informe preliminar de los cruceros SNP-1 y Unanue 7204

Presenta información sobre la alteración oceanográfica del verano pasado, provocada por la invasión de aguas tropicales superficiales que cubrieron la costa norte. El estudio se realizó entre el 25 de abril y el 3 de mayo 1972 a lo largo de la costa sur del Perú.

Fitoplancton del mar peruano durante el verano austral 2001

Analiza los volúmenes de plancton, la composición y distribución del fitoplancton de red y de agua en la columna de 0-50 metros de profundidad; y técnicas de estimación de la producción biológica (análisis de integración y concentración celular)

Pièces diverses, manuscrites et imprimées, concernant les affaires ecclésiastiques en Lorraine (VIIIe-XVIIIe siècle). XVI — 752-1729. — Abbayes et prieurés (IV).

Contient : Épinal (1303-1661) ; Etival (1554-1719) ; Flabémont, mss. et impr., in-4° (1526-1675) ; Flavigny : comptes des revenus du prieuré (1657) ; Freistroff (1644-1712) ; Gorze : copies et factums, impr., in-4° (752-XVIIe siècle) ; Grafenthal (1554-1556) ; Grimaucourt-près-Sampigny (1639-1720) ; Hauteseille (1585) ; Herbitzheim ; originaux et copies (1284-XVIe siècle) ; Hornbach (1513)

Mémoires de Mme Roland. Tome 2 / , avec une notice sur sa vie, des notes et des éclaircissements historiques par MM. Berville et Barrière...

Collection : Collection des mémoires relatifs à la Révolution française

Mémoires de Mme Roland. Tome 1 / , avec une notice sur sa vie, des notes et des éclaircissements historiques par MM. Berville et Barrière...

Collection : Collection des mémoires relatifs à la Révolution française