Three amphioxus reference genomes reveal gene and chromosome evolution of chordates

The slow-evolving invertebrate amphioxus has an irreplaceable role in advancing our understanding into the vertebrate origin and innovations. Here we resolve the nearly complete chromosomal genomes of three amphioxus species, one of which best recapitulates the 17 chordate ancestor linkage groups. We reconstruct the fusions, retention or rearrangements between descendants of whole genome duplications (WGDs), which gave rise to the extant microchromosomes likely existed in the vertebrate ancestor. Similar to vertebrates, the amphioxus genome gradually establishes its 3D chromatin architecture at the onset of zygotic activation, and forms two topologically associated domains at the Hox gene cluster. We find that all three amphioxus species have ZW sex chromosomes with little sequence differentiation, and their putative sex-determining regions are nonhomologous to each other. Our results illuminate the unappreciated interspecific diversity and developmental dynamics of amphioxus genomes, and provide high-quality references for understanding the mechanisms of chordate functional genome evolution.

HSC-independent definitive hematopoietic cells persist into adult life

SummaryThe stem cell theory that all blood cells are derived from hematopoietic stem cell (HSC) is a central dogma in hematology. However, various types of blood cells are already produced from hemogenic endothelial cells (HECs) before the first HSCs appear at embryonic day (E)11 in the mouse embryo. This early blood cell production from HECs, called HSC-independent hematopoiesis, includes primitive and definitive erythromyeloid progenitors that transiently support fetal blood homeostasis until HSC-derived hematopoiesis is established. Lymphoid potential has traditionally been detected in the extra-embryonic yolk sac (YS) and/or embryos before HSC emergence, but the actual presence of lymphoid progenitors at this stage remains unknown. In addition, whether HSCs in the fetal liver are the main source of innate-like B-1a cells has been controversial. Here, using complementary lineage tracing mouse models, we show that HSC-independent multipotent progenitors (MPPs) and HSC-independent adoptive B-lymphoid progenitors persist into adult life. Furthermore, HSCs minimally contribute to the peritoneal B-1a cell pool; most B-1a cells are originated directly from ECs in the YS and embryo and HSC-independent for life. Our discovery of extensive HSC-independent MPP and B-lymphoid progenitors in adults attests to the complex blood developmental dynamics through embryo to adult that underpin the immune system and challenges the paradigm of HSC theory in hematology.

Uncovering natural variation in root system architecture and growth dynamics using a robotics-assisted phenomics platform

The plant kingdom contains a stunning array of complex morphologies easily observed above ground, but largely unexplored below-ground. Understanding the magnitude of diversity in root distribution within the soil, termed root system architecture (RSA), is fundamental to determining how this trait contributes to species adaptation in local environments. Roots are the interface between the soil environment and the shoot system and therefore play a key role in anchorage, resource uptake, and stress resilience. Previously, we presented the GLO-Roots (Growth and Luminescence Observatory for Roots) system to study the RSA of soil-grown Arabidopsis thaliana plants from germination to maturity. In this study, we present the automation of GLO-Roots using robotics and the development of image analysis pipelines in order to examine the natural variation of RSA in Arabidopsis over time. This dataset describes the developmental dynamics of 93 accessions and reveals highly complex and polygenic RSA traits that show significant correlation with climate variables.

The role of local knowledge system in enhancing Peranakan Etawa goat farm

The local livestock knowledge system is seen as the contributor to agricultural and rural development but not all local knowledge has the opportunities to be explored, customized, and applied to follow developmental dynamics. This research aimed to analyze the local livestock knowledge system of Peranakan Etawa (PE) goats from its elements, roles, management, and knowledge dissemination. This study was conducted in Kaligesing Subdistrict, Purworejo Regency, Central Java using qualitative methods. The data were obtained through interviews, observation, and documentation. Participants were determined purposively which consisted of smallholder farmers. The data validity was checked using triangulation of data sources and methods. Data analysis included data collection, data reduction, data presentation, data interpretation, and data collection. The results indicated that the PE goat farming local knowledge system elements existed by the integration of traditional and scientific knowledge systems that were distributed and applied by the farmers’ community as a source of livestock knowledge. Management and dissemination of local knowledge use the combination of traditional and modern patterns.

Feminization of Indian Migration: Patterns and Prospects

The migration of women or female migration has emerged as an important field of research within the larger domain of migration studies and is being extensively explored under various disciplines. This growing trend can be attributed to some major developments in international migration such as rising numbers of women migrants, growth of women-centric occupations, migration of women in an independent capacity, women-related legislations and growth of gendered perspectives on various issues. These factors together increased the visibility of women in the migration process and have given rise to what has been termed the ‘feminization of migration’. This paper explores the various nuances of the feminization of migration and aspects of female migration focusing on India. It begins with an overview of the growing numbers of women in the migratory flows and goes on to determine that despite the rising numbers and increased participation of women in the developmental dynamics of migration, they remain increasingly vulnerable and exposed to exploitation. The paper also highlights some of the critical policy decisions of the Government of India. The paper concludes that feminization of migration has undoubtedly increased the visibility of women in the migration discourse but much more needs to be done in terms of generating appropriate data, highlighting women’s role in the developmental process, evolving policies for ensuring their protection and security and above all empowering them and increasing their participation in the labour market.