Haploids and double haploids are important resources for studying recessive traits and have large impacts on crop breeding, but natural haploids are rare in animals. Mammalian haploids are restricted to germline cells and are occasionally found in tumours with massive chromosome loss. Recent success in establishing haploid embryonic stem (ES) cells in medaka fish and mice raised the possibility of using engineered mammalian haploid cells in genetic studies. However, the availability and functional characterization of mammalian haploid ES cells are still limited. Here we show that mouse androgenetic haploid ES (ahES) cell lines can be established by transferring sperm into an enucleated oocyte. The ahES cells maintain haploidy and stable growth over 30 passages, express pluripotent markers, possess the ability to differentiate into all three germ layers in vitro and in vivo, and contribute to germlines of chimaeras when injected into blastocysts. Although epigenetically distinct from sperm cells, the ahES cells can produce viable and fertile progenies after intracytoplasmic injection into mature oocytes. The oocyte-injection procedure can also produce viable transgenic mice from genetically engineered ahES cells. Our findings show the developmental pluripotency of androgenentic haploids and provide a new tool to quickly produce genetic models for recessive traits. They may also shed new light on assisted reproduction.

Rosa roxburghii Tratt is a natural fruit that contains unique functional and nutritional constituents, which are characterised by a high anti-oxidant potential.

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Haploid pluripotent stem cells, such as haploid embryonic stem cells (haESCs), facilitate the genetic study of recessive traits. In vitro, fish haESCs maintain haploidy in both undifferentiated and differentiated states, but whether mammalian haESCs can preserve pluripotency in the haploid state has not been tested. Here, we report that mouse haESCs can differentiate in vitro into haploid epiblast stem cells (haEpiSCs), which maintain an intact haploid genome, unlimited self-renewal potential, and durable pluripotency to differentiate into various tissues in vitro and in vivo. Mechanistically, the maintenance of self-renewal potential depends on the Activin/bFGF pathway. We further show that haEpiSCs can differentiate in vitro into haploid progenitor-like cells. When injected into the cytoplasm of an oocyte, androgenetic haEpiSC (ahaEpiSCs) can support embryonic development until midgestation (E12.5). Together, these results demonstrate durable pluripotency in mouse haESCs and haEpiSCs, as well as the valuable potential of using these haploid pluripotent stem cells in high-throughput genetic screening.

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Multidrug and Toxic Compound Extrusion (MATEs) is one of the characteristic transporter families, which plays a key role in the detoxication of endogenous secondary metabolites and exogenous agents in both animal and plant cells. In this study, we identified a total of 67 MATE genes (CcMATEs) from the pigeonpea genome, on which we performed bioinformatics analysis and we group them by phylogenetic analysis. Finally, eight represented CcMATE genes were selected for further qRT-PCR analysis of tissue specificity and response to metal stress in pigeonpea. The results showed that both CcMATE34 and 45 genes were significantly up-regulated and the CcMATE4 gene was only up-regulated in the roots under the stress of Al, Mn and Zn. We speculated that the function of CcMATE34 and 45 might be related to the transport of alkaloids and harmful substances and the function of CcMATE4 might be related to the delivery of flavonoids.

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