Molecular Evolution of Tubulins in Diatoms

Microtubules are formed by α- and β-tubulin heterodimers nucleated with γ-tubulin. Tubulins are conserved eukaryotic proteins. Previously, it was shown that microtubules are involved in diatom silica frustule morphogenesis. Diatom frustules are varied, and their morphology is species-specific. Despite the attractiveness of the problem of elucidating the molecular mechanisms of genetically programmed morphogenesis, the structure and evolution of diatom tubulins have not been studied previously. Based on available genomic and transcriptome data, we analyzed the phylogeny of the predicted amino acid sequences of diatom α-, β- and γ-tubulins and identified five groups for α-tubulins, six for β-tubulins and four for γ-tubulins. We identified characteristic amino acids of each of these groups and also analyzed possible posttranslational modification sites of diatom tubulins. According to our results, we assumed what changes occurred in the diatom tubulin structures during their evolution. We also identified which tubulin groups are inherent in large diatom taxa. The similarity between the evolution of diatom tubulins and the evolution of diatoms suggests that molecular changes in α-, β- and γ-tubulins could be one of the factors in the formation of a high morphological diversity of diatoms.

Two new species of Ageniella Banks, 1912 (Hymenoptera: Pompilidae) from Brazil and updated keys

Ageniella Banks, 1912 is a paraphyletic group exclusive to the Nearctic and Neotropical regions. The genus has a remarkable morphological diversity among species and strong sexual dimorphism, hampering taxonomic studies of it. Herein, we add two new species to the Neotropical fauna of Ageniella: A. caerulea sp. nov. belonging to the subgenus Ameragenia and A. ruschi sp. nov. belonging to the subgenus Priophanes; both species are described and illustrated. A brief discussion of subgeneric characters and an updated taxonomic key to the species of Ageniella known from Brazil are provided.

Genome structure and diversity among Cynanchum wilfordii accessions

Background Cynanchum wilfordii (Cw) and Cynanchum auriculatum (Ca) have long been used in traditional medicine and as functional food in Korea and China, respectively. They have diverse medicinal functions, and many studies have been conducted, including pharmaceutical efficiency and metabolites. Especially, Cw is regarded as the most famous medicinal herb in Korea due to its menopausal symptoms relieving effect. Despite the high demand for Cw in the market, both species are cultivated using wild resources with rare genomic information. Results We collected 160 Cw germplasm from local areas of Korea and analyzed their morphological diversity. Five Cw and one Ca of them, which were morphologically diverse, were sequenced, and nuclear ribosomal DNA (nrDNA) and complete plastid genome (plastome) sequences were assembled and annotated. We investigated the genomic characteristics of Cw as well as the genetic diversity of plastomes and nrDNA of Cw and Ca. The Cw haploid nuclear genome was approximately 178 Mbp. Karyotyping revealed the juxtaposition of 45S and 5S nrDNA on one of 11 chromosomes. Plastome sequences revealed 1226 interspecies polymorphisms and 11 Cw intraspecies polymorphisms. The 160 Cw accessions were grouped into 21 haplotypes based on seven plastome markers and into 108 haplotypes based on seven nuclear markers. Nuclear genotypes did not coincide with plastome haplotypes that reflect the frequent natural outcrossing events. Conclusions Cw germplasm had a huge morphological diversity, and their wide range of genetic diversity was revealed through the investigation with 14 molecular markers. The morphological and genomic diversity, chromosome structure, and genome size provide fundamental genomic information for breeding of undomesticated Cw plants.

Exploration and morphologic variation of Iris wild species with ornamental potential

Nowadays, the flower industry is growing so fast that its development requires introducing new varieties to the flower market. Iran is the habitat of numerous species of wild plants that are among the valuable genetics in the breeding process. The identification of native Iris species, investigation of morphological diversity, and distribution method have a significant effect on the introduction of this flower as new and superior cultivars cut flower and bedding plant. The documentation of the most important habitats of Iris in Arak province, identification of morphological characteristics and correlation determination of morphological traits are the most important aims of this research. The results showed that there is a correlation between some of the traits. The highest positive correlation was related to the height of flower and length of the leaf, length of the flowering stem and the length of the leaf and the height of the flower and the length of the flowering stem. The ecotypes of Iris sp. were divided into six groups. Based on the results of the cluster diagram, the bulbous species were separated from rhizome species. Generally, due to the color diversity of Iris sp. and unique beauty of the flowers and the resistance of the native species, they can be used as native foundations. Due to the prominent traits such as high durability of Iris meda, odor of I. hymernospatha Subsp. leptoneura and color diversity of I. persica, I. songarica and height of I. spuria, they can be used to introduce new ornamental species. Iris spuria is the most suitable genotype because of the high height, large flower, high durability, and beautiful flower.

Tracing the evolution of bioluminescent light organs across the deep-sea shrimp family Sergestidae using a genomic skimming and phylogenetic approach

Deep-sea shrimp of the family Sergestidae Dana, 1852 provide a unique system for studying the evolution of bioluminescence. Most species within the family possess autogenic bioluminescent photophores in one of three distinct forms: lensed photophores; non-lensed photophores; or internal organs of Pesta. This morphological diversity across the Sergestidae has resulted in recent major taxonomic revisions, dividing the two major genera (Sergia Stimpson, 1860 and Sergestes Milne Edwards, 1830) into 15. The present study capitalises on molecular data to construct an updated genus-level phylogeny of sergestid shrimp. DNA was successfully extracted from ~87 individuals belonging to 13 of the 15 newly proposed genera. A ‘genome skimming’ approach was implemented, allowing the capture of mitochondrial genomic data across 19 sergestid species. Additional individuals have been incorporated into the phylogeny through Sanger sequencing of both nuclear (H3 and NAK) and mitochondrial (16S and COI) genes. The resulting molecular phylogeny is compared with previous morphological trees with specific attention to genus-level relationships. The -sergestes group was rendered non-monophyletic and the -sergia group was recovered as monophyletic. Ancestral state reconstructions of light organ type indicate that organs of Pesta is the ancestral state for the family. Non-lensed photophores evolved once across the -sergia group, but were later lost in the deepest living genus, Sergia. Lensed photophores also evolved once within the genera Prehensilosergia Vereshchaka, Olesen & Lunina, 2014, Lucensosergia Vereshchaka, Olesen & Lunina, 2014 and Challengerosergia Vereshchaka, Olesen & Lunina, 2014. These findings identify preliminary patterns across light organ type and species’ depth distributions; however, future research that incorporates finer-scale depth data and more species is needed to confirm our findings.

IN-SITU MORPHOLOGICAL CHARACTERIZATION OF CASSAVA LANDRACES (MANIHOTESCULENTACRANTZ) FROM COTE DIVOIRE

Cassava provides food security for millions of people worldwide. In Cote dIvoire, it is the second most important food crop. The objective of this study is to evaluate the structure and genetic variability of certain qualitative traits in targeted cassava landracesin order to identify the most widespread cassava landraces. Thus, prospecting missions were carried out in different regions of Cote dIvoire to characterize cassavalandraces, from which 180 cassava landrace accessions were characterized using14 morphological markers. Multiple Correspondence Analysis (MCA) showed that among the 14 markers, 10 were relevant fordescribing the total variability within accessions. In addition, the Hierarchical Ascending Classification (HAC) grouped the Ivorianlandraces into five homogeneous groups and also revealed that this morphological diversity is not structured according to the landracesgeographical origin. The study highlighted 131 distinct cultivars among the 180 accessions characterized. Moreover, of the 131 distinct cultivars, four were the most widespread. These are the local cultivars: Yace, Six mois, Blêbou and Trogla. Thus, the study has definitively shown that breeders have a wide choice of parents for developing improved cassava cultivars adapted fromthe populations found in Cote dIvoire.