The Phylogeny and Expression Pattern of APETALA2-like Genes in Rice

The multigene families undergo birth-and-death evolution and thus contribute to biological innovations. The APETALA2-1ike genes belong to the euAP2 group of the AP2 gene family. These genes are characterized by several distinct motifs and exist in ferns, gymnosperms, and angiosperms. The phylogenetic analysis indicated that these genes have undergone the birth-and-death evolution. The five APETALA2-1ike genes in rice （Oryza sativa L.） display redundant but distinct expression patterns as demonstrated by RT-PCR and in situ hybridization. The potential functions of these genes were discussed on the basis of phylogenetic and expression pattern.

An update on the function and regulation of methylerythritol phosphate and mevalonate pathways and their evolutionary dynamics

Isoprenoids are among the largest and most chemically diverse classes of organic compounds in nature and are involved in the processes of photosynthesis, respiration, growth, development,and plant responses to stress. The basic building block units for isoprenoid synthesis-isopentenyl diphosphate and its isomer dimethylallyl diphosphate-are generated by the mevalonate (MVA) and methylerythritol phosphate(MEP) pathways. Here, we summarize recent advances on the roles of the MEP and MVA pathways in plant growth, development and stress responses, and attempt to define the underlying gene networks that orchestrate the MEP and MVA pathways in response to developmental or environmental cues.Through phylogenomic analysis, we also provide a new perspective on the evolution of the plant isoprenoid pathway. We conclude that the presence of the MVA pathway in plants may be associated with the transition from aquatic to subaerial and terrestrial environments, as lineages for its core components are absent in green algae. The emergence of the MVA pathway has acted as a key evolutionary event in plants that facilitated land colonization and subsequent embryo development, as well as adaptation to new and varied environments.

Do key innovations unlock diversification?A case-study on the morphological and ecological impact of pharyngognathy in acanthomorph fishes

Key inn ovations may allow lin eages access to new resources and facilitate the invasi on of new adaptive zon es,potentially influencing diversificati on patter ns.Many studies have focused on the impact of key inno vations on speciation rates,but far less is known about how they influe nee phe notypic rates and patterns of ecomorphological diversification.We use the repeated evolution of pharyngognathy within acanthomorph fishes,a commonly cited key innovation,as a case study to explore the predicti ons of key inn ovation theory.Specifically,we in vestigate whether transiti ons to phary ngognathy led to shifts in the rate of phenotypic evolution,as well as shifts and/or expansion in the occupation of morphological and dietary space,using a dataset of 8 morphological traits measured across 3,853 species of Acanthomorpha.Analyzing the 6 evolutionarily independent pharyngognathous clades together,we found no evidence to support pharyngognathy as a key innovation;however,comparisons between individual pharyngognathous lineages and their sister clades did reveal some consistent patterns.In morphospace,most pharyngognathous clades cluster in areas that correspond to deeper-bodied morphologies relative to their sister clades,whereas occupying greater areas in dietary space that reflects a more diversified diet Additi on ally,both Cichlidae and Labridae exhibited higher univariate rates of phenotypic evolution compared with their closest relatives.However,few of these results were exceptional relative to our null models.Our results suggest that transitions to pharyngognathy may only be advantageous when combined with additional ecological or intrinsic factors,illustrating the importance of account!ng for lineage-specific effects when testing key innovation hypotheses.Moreover,the challenges we experienced formulating informative comparisons,despite the ideal evolutionary scenario of multiple independent evolutionary origins of pharyngognathous clades,illustrates the complexities involved in quantifying the impact of key innovations.Given the issues of lineage specific effects and rate heterogeneity at macroevolutionary scales we observed,we suggest a reassessment of the expected impacts of key innovations may be warranted.