Interspecies somatic cell nuclear transfer (iSCNT) has an immense potential to rescue endangered animals and extinct species like mammoths. In this study, we successfully established an Asian elephant’s fibroblast cell lines from ear tissues, performed iSCNT with porcine oocytes and evaluated the in vitro and in vivo development of reconstructed embryos. A total of 7780 elephant–pig iSCNT embryos were successfully reconstructed and showed in vitro development with cleavage rate, 4-cell, 8-cell and blastocyst rate of 73.01, 30.48, 5.64, and 4.73%, respectively. The total number of elephant–pig blastocyte cells and diameter of hatched blastocyte was 38.67 and 252.75 μm, respectively. Next, we designed species-specific markers targeting EDNRB, AGRP and TYR genes to verify the genome of reconstructed embryos with donor nucleus/species. The results indicated that 53.2, 60.8, and 60.8% of reconstructed embryos (n = 235) contained elephant genome at 1-cell, 2-cell and 4-cell stages, respectively. However, the percentages decreased to 32.3 and 32.7% at 8-cell and blastocyst stages, respectively. Furthermore, we also evaluated the in vivo development of elephant–pig iSCNT cloned embryos and transferred 2260 reconstructed embryos into two surrogate gilts that successfully became pregnant and a total of 11 (1 and 10) fetuses were surgically recovered after 17 and 19 days of gestation, respectively. The crown-rump length and width of elephant–pig cloned fetuses were smaller than the control group. Unfortunately, none of these fetuses contained elephant genomes, which suggested that elephant embryos failed to develop in vivo. In conclusion, we successfully obtained elephant–pig reconstructed embryos for the first time and these embryos are able to develop to blastocyst, but the in vivo developmental failure needs further investigated.

The AT-hook motif nuclear localized (AHL) gene family encodes transcription factors pivotal in regulating plant growth, development, and responses to abiotic stimuli, including low temperature, salinity, darkness, and drought. In this study, we systematically identified 21 BpAHL genes in birch and characterized their sequence features, evolutionary relationships, and expression dynamics. Phylogenetic analysis classified BpAHLs into two clades (Clade-A and Clade-B) and three types (Type-I, -II, and -III), based on PPC domain and AT-hook motifs. Chromosomal mapping revealed an even distribution across nine chromosomes and one contig, with dispersed duplication events recognized as the major driver of BpAHL family expansion. Tissue-specific expression profiling uncovered striking divergence: Type-I BpAHLs displayed root-predominant expression, whereas Type-II/III BpAHLs were highly expressed in plant flowers and leaves. Notably, Type-II/III BpAHL genes in leaves showed distinct expression patterns in response to cold and heat stresses, while Type-I BpAHLs in roots were down-regulated under salt stress. This study provides a comprehensive phylogenomic and functional analysis of the AHLs in birch, providing insights into their roles in enhancing abiotic stress resilience in forest trees.

Although chromatin states are closely associated with epigenetic modifications, how they influence each other remains to be fully elucidated. In this study, we found that mutation of DECREASED IN DNA METHYLATION 1 (DDM1) in soybean leads to genome-wide chromatin homogenization, characterized by a loosening of heterochromatin and a tightening of euchromatin. This remodeling triggers 2 distinct molecular pathways: in heterochromatin, increased release of small RNAs activates the noncanonical RdDM pathway; while in euchromatin, transposable elements (TEs) are enriched with H3K9me2 modifications, which in turn activate the CMT2 pathway. Together, these pathways drive a pronounced burst of CHH methylation at the whole genome level. This epigenetic remodeling correlates with massive transcriptional dysregulation, upregulating stress responses and downregulating photosynthesis, linking local H3K9me2 changes on TEs, ultimately leading to severe phenotypes. Our findings reveal a unique, bidirectional pathway for CHH regulation in plants with complex chromatin states remodeling.