Author: Bernard Goffinet

Thank you to Dr. Jane O’Donnell

Dr. Jane O’Donnell officially retired from her position as Invertebrate Collection Manager. Jane had been at UCONN for 39 years, completing her undergraduate and graduate degree before serving as collection manager. Jane distinguished herself by her unconditional commitment to the collection, providing numerous opportunities for undergraduates to acquire experiences in natural history collection management, leading a course on the role and significance of natural history collections and devoting her career to the preservation, accessibility and growth of the invertebrate collection. Jane has been an inspiration to all who had the chance to work with her. She will now focus more of her time to completing some of her outstanding projects on the systematics of the true bugs (i.e., Heteroptera). Thank you for your many years of exemplary service and best wishes, from everyone in the Biodiversity Research Collections.

Vouchers for genome studies

Vouchers, that is the material from which DNA was extracted for this latest study below, are deposited in the CONN herbarium. Why are such vouchers needed, now that part of their genome is sequenced?  Species boundaries in bryophytes are constantly reassessed, and primarily based on inferences from molecular data. Ultimately, the structure in genetic and phylogenetic diversity should or may want to be contrasted to patterns of variation in morphological traits, which can only be gathered from the specimens. By preserving the biological material, we maintain the opportunity to integrate its genetic and morphological traits in a broader study. And technologies change. Nothing replaces an actual specimen.Who would have predicted 40 years ago that DNA could be extracted from preserved specimens for sequencing? Maybe Michael Crichton!

Dong S., C. Zhao, S. Zhang, L. Zhang, H. Wu, R. Zhu, Y. Jia, B. Goffinet & Y. Liu. 2020. Mitochondrial genomes of the early land plant lineage liverworts (Marchantiophyta): conserved genome structure, and ongoing low frequency recombination. BMC Genomics 20: 953. pdf

Abstract readsBackground: In contrast to the highly labile mitochondrial (mt) genomes of vascular plants, the architecture and composition of mt genomes within the main lineages of bryophytes appear stable and invariant. The available mt genomes of 18 liverwort accessions representing nine genera and five orders are syntenous except for Gymnomitrion concinnatumwhose genome is characterized by two rearrangements. Here, we expanded the number of assembled liverwort mt genomes to 47, broadening the sampling to 31 genera and 10 orders spanning much of the phylogenetic breadth of liverworts to further test whether the evolution of the liverwort mitogenome is overall static. Results: Liverwort mt genomes range in size from 147 Kb in Jungermanniales (clade B) to 185 Kb in Marchantiopsida, mainly due to the size variation of intergenic spacers and number of introns. All newly assembled liverwort mt genomes hold a conserved set of genes, but vary considerably in their intron content. The loss of introns in liverwort mt genomes might be explained by localized retroprocessing events. Liverwort mt genomes are strictly syntenous in genome structure with no structural variant detected in our newly assembled mt genomes. However, by screening the paired-end reads, we do find rare cases of recombination, which means multiple concurrent genome structures may exist in the vegetative tissues of liverworts. Our phylogenetic analyses of the nuclear encoded double stand break repair protein families revealed liverwort-specific subfamilies expansions. Conclusions: The low repeat recombination level, selection, along with the intensified nuclear surveillance, might together shape the structural evolution of liverwort mt genomes.

New publication on liverworts

Some vouchers contributed to this study are deposited in the CONN herbarium.  Dong S., C. Zhao, S. Zhang, H. Wu, W. Mu, T. Wei, N. Li, H. Liu, J. Cui, R. Zhu, B. Goffinet & Y. Liu. 2020. The amount of RNA editing sites in liverwort organellar genes is correlated with GC content and nuclear PPR protein diversity. Genome Biology and Evolution 11: 3233–3239. pdf

Abstract reads: RNA editing occurs in the organellar mRNAs of all land plants but the marchantioid liverworts, making liverworts a perfect group for studying the evolution of RNA editing. Here, we profiled the RNA editing of 42 exemplars spanning the ordinal phylogenetic diversity of liverworts, and screened for the nuclear-encoded pentatricopeptide repeat (PPR) proteins in the transcriptome assemblies of these taxa.We identified 7,428 RNA editing sites in 128 organellar genes from 31 non-marchantioid liverwort species, and characterized 25,059 PPR protein sequences. The abundance of organellar RNA editing sites varies greatly among liverwort lineages, genes, and codon positions, and shows strong positive correlations with the GC content of protein-coding genes, and the diversity of the PLS class of nuclear PPR proteins.

Summer interns in collections

Ginger speciesThe BRC endowment provided opportunities for students to work in the collections during the summer. In the living plant collection, the student attended to essential horticultural task and help with the acquisition of a significant collection of Zingiberales (ginger relatives, over 200 species) which will greatly enhance the UConn living collections and directly support EEB faculty looking at a number of important questions utilizing the ginger family as a model system.  A number of the recently acquired gingers are also new to science and will hopefully be described and published in the near future.

In the vertebrate collection, student completed checking the fluid levels of the spirit preserved collection of fish, reptiles and amphibians, deaccessioning specimens that were dried out, or lacking data. Finally, all peccary skulls are now kept in archival boxes.

Thank you to the supporters of the BRC that make these internships possible.

 

Weevil curation: done!

Stan MalcolmDr. Stan Malcolm, an UCONN alum in Systematics and Entomology, has volunteered since 2017, to assist in the curation of the insect collection. He has reorganized several families of beetles, and he is shown here with his latest accomplishment: the weevils. The taxonomy of this group is now current, with all specimens transferred to new unit trays, and all trays with new labels. Great Job Dr. Malcolm!