bims-plasge 2025-02-09 papers

Issue of 2025–02–09
three papers selected by
Vera S. Bogdanova, ИЦиГ СО РАН

Dev Cell. 2025 Jan 30. pii: S1534-5807(25)00033-4. [Epub ahead of print]

Asymmetric partitioning of persistent paternal mitochondria during cell divisions safeguards embryo development and mitochondrial inheritance.

Songyun Wang, Ding Xue.

Most eukaryotes inherit only maternal mitochondria. The reasons for paternal mitochondrial elimination and the impacts of persistent paternal mitochondria on animals remain elusive. We show that undegraded paternal mitochondria in autophagy-deficient C. elegans embryos are gradually excluded from germ blastomeres through asymmetric partitioning during cell divisions. The embryonic cortical flow drives anterior-directed movements of paternal mitochondria and contributes to their asymmetric apportioning between two daughter blastomeres. By contrast, autophagosome-enclosed paternal mitochondria cluster around and segregate with centrosomes during mitosis and are rapidly degraded through lysosomes concentrated near centrosomes. Failure to exclude persistent paternal mitochondria from the germ blastomere at first cleavage causes their enrichment in the descendant endomesodermal (EMS) blastomere, leading to elevated reactive oxygen species levels, elongated EMS lineage durations, and increased embryonic lethality, which antioxidant treatments can suppress. Thus, regulated paternal mitochondrial distribution away from germ blastomeres is a fail-safe mechanism, protecting embryo development and maternal mitochondrial inheritance.

Keywords: C. elegans; PME; ROS; asymmetric partitioning of mitochondria; autophagy; cortical flow; embryo development; germline blastomere; mitochondrial inheritance; paternal mitochondrial elimination; reactive oxygen species

DOI: https://doi.org/10.1016/j.devcel.2025.01.013

Front Plant Sci. 2025 ;16 1489244

Taming wild genomes: perspectives on mechanisms governing differential introgression in exotic rice germplasm and their applications in breeding.

Avinash Shrestha, Christian J Stephens, Rosalyn B Angeles-Shim.

Wide hybridization is an important plant breeding strategy that can be used to expand the available genetic variation in present-day crops towards breeding for enhanced agronomic performance. The primary challenge in wide hybridization is the presence of reproductive barriers and genetic incompatibilities that limit the transfer of desirable wild or distant alleles in the genetic background of cultivated plant species. Here we provide perspectives on the possible role of hybrid sterility and gametocidal genes on the observed preferential introgression in exotic germplasm of rice. We argue that while these aberrant introgression and segregation behavior of wild or distant chromosomes presents significant barriers in exploiting ancestral germplasm in breeding, the same mechanisms can also be exploited to enhance the transfer of wild alleles in a cultivated genetic background. Understanding the genetic basis of preferential introgression and segregation in wide hybrids will have serious implications in our ability to capture ancestral genetic variation that can add significant agronomic value to staple crops like rice.

Keywords: chromosome introgression; distant relatives; gametocidal genes; preferential chromosome transfer; wide hybridization

DOI: https://doi.org/10.3389/fpls.2025.1489244

Theor Appl Genet. 2025 Feb 08. 138(2): 47

The evolutionary history of the common bean (Phaseolus vulgaris) revealed by chloroplast and nuclear genomes analysis.

Giulia Frascarelli, Teresa R Galise, Nunzio D'Agostino, Donata Cafasso, Salvatore Cozzolino, Gaia Cortinovis, Francesca Sparvoli, Elisa Bellucci, Valerio Di Vittori, Laura Nanni, Alice Pieri, Marzia Rossato, Leonardo Vincenzi, Andrea Benazzo, Massimo Delledonne, Elena Bitocchi, Roberto Papa.

KEY MESSAGE: The origin of common bean was investigated throughout chloroplast and nuclear WGS data considering recombination events. Our results support the Mesoamerican origin of common bean. The remarkable evolutionary history of the common bean (Phaseolus vulgaris L.) has led to the emergence of three wild main gene pools corresponding to three different eco-geographical areas: Mesoamerica, the Andes and northern Peru/Ecuador. Recent works proposed novel scenarios, and the northern Peru/Ecuador population has been described as a new species called P. debouckii, rekindling the debate about the origin of P. vulgaris. Here we shed light on the origin of P. vulgaris by analyzing the chloroplast and nuclear genomes of a large varietal collection representing the entire geographical distribution of wild forms including a large collection of Mesoamerican and Andean individuals. We assembled 37 chloroplast genomes de novo and used them to construct a time frame for the divergence of the genotypes under investigation, revealing that the separation of the Mesoamerican and northern Peru/Ecuador gene pools occurred ~ 0.15 Mya. Our results clearly support a Mesoamerican origin of the common bean and reject the recent P. deboukii hypothesis. These results also imply two independent migratory events from Mesoamerica to the North and South Andes, probably facilitated by birds. Our work represents a paradigmatic example of the importance of taking into account the genetic rearrangements produced by recombination when investigating phylogeny and of the analysis of wild forms when studying the evolutionary history of a crop species.

DOI: https://doi.org/10.1007/s00122-025-04832-z