Annual Review of Animal Biosciences最新文献

Nutrition security is challenging in regions where resources are limited and food production is naturally constrained. In low- and middle-income countries (LMICs), undernutrition is high for many reasons, including lack of nutritional diversity and low high-quality protein content. Interest in the role of animal-source food (ASF) in reducing nutrition insecurity is increasing, as evidence from LMICs suggests that consumption of ASF is strongly associated with reduction in stunting, improved diet quality, and overall nutrition, particularly in early stages of life. We review the strengths and limitations of ASF consumption in terms of accessibility, safety, and nutritional benefits compared to non-ASF sources. We present a critical discussion on existing barriers to ASF consumption and its future directions in LMICs. Understanding the role of ASF in improving nutrition security in LMICs is crucial to optimizing public health, designing appropriate interventions, and implementing effective policy in resource-poor settings.

Transcriptional regulation in response to diverse physiological cues involves complicated biological processes. Recent initiatives that leverage whole genome sequencing and annotation of regulatory elements significantly contribute to our understanding of transcriptional gene regulation. Advances in the data sets available for comparative genomics and epigenomics can identify evolutionarily constrained regulatory variants and shed light on noncoding elements that influence transcription in different tissues and developmental stages across species. Most epigenomic data, however, are generated from healthy subjects at specific developmental stages. To bridge the genotype-phenotype gap, future research should focus on generating multidimensional epigenomic data under diverse physiological conditions. Farm animal species offer advantages in terms of feasibility, cost, and experimental design for such integrative analyses in comparison to humans. Deep learning modeling and cutting-edge technologies in sequencing and functional screening and validation also provide great promise for better understanding transcriptional regulation in this dynamic field.

Chromosome engineering is a transformative field at the cutting edge of biological science, offering unprecedented precision in manipulating large-scale genomic DNA within cells. This discipline is central to deciphering how the multifaceted roles of chromosomes-guarding genetic information, encoding sequence positional information, and influencing organismal traits-shape the genetic blueprint of life. This review comprehensively examines the technological advancements in chromosome engineering, which center on engineering chromosomal rearrangements, generating artificial chromosomes, de novo synthesizing chromosomes, and transferring chromosomes. Additionally, we introduce the application progress of chromosome engineering in basic and applied research fields, showcasing its capacity to deepen our knowledge of genetics and catalyze breakthroughs in therapeutic strategies. Finally, we conclude with a discussion of the challenges the field faces and highlight the profound implications that chromosome engineering holds for the future of modern biology and medical applications.

The northern white rhinoceros (NWR) is functionally extinct, with only two nonreproductive females remaining. However, because of the foresight of scientists, cryopreserved cells and reproductive tissues may aid in the recovery of this species. An ambitious program of natural and artificial gametes and in vitro embryo generation was first outlined in 2015, and many of the proposed steps have been achieved. Multiple induced pluripotent stem cell lines have been established, primordial germ cell-like cells have been generated, oocytes have been collected from the remaining females, blastocysts have been cryopreserved, and the closely related southern white rhinoceros (SWR) is being established as a surrogate. Recently, the first successful embryo transfer in SWR demonstrated that embryos can be generated by in vitro fertilization and cryopreserved. We explore progress to date in using advanced cellular technologies to save the NWR and highlight the necessary next steps to ensure a viable population for reintroduction. We roll out a holistic rescue approach for a charismatic megavertebrate that includes the most advanced cellular technologies, which can provide a blueprint for other critically endangered mammals. We also provide a detailed discussion of the remaining questions in such an upgraded conservation program.

Hummingbirds share biologically distinctive traits: sustained hovering flight, the smallest bird body size, and high metabolic rates fueled partially by nectar feeding that provides pollination to plant species. Being insectivorous and sometimes serving as prey to larger birds, they fulfill additional important ecological roles. Hummingbird species evolved and radiated into nearly every habitat in the Americas, with a core of species diversity in South America. Population declines of some of their species are increasing their risk of extinction. Threats to population health and genetic diversity are just beginning to be identified, including diseases and hazards caused by humans. We review the disciplines of population health, disease ecology, and genomics as they relate to hummingbirds. We appraise knowledge gaps, causes of morbidity and mortality including disease, and threats to population viability. Finally, we highlight areas of research need and provide ideas for future studies aimed at facilitating hummingbird conservation.

End-stage organ failure can result from various preexisting conditions and occurs in patients of all ages, and organ transplantation remains its only treatment. In recent years, extensive research has been done to explore the possibility of transplanting animal organs into humans, a process referred to as xenotransplantation. Due to their matching organ sizes and other anatomical and physiological similarities with humans, pigs are the preferred organ donor species. Organ rejection due to host immune response and possible interspecies infectious pathogen transmission have been the biggest hurdles to xenotransplantation's success. Use of genetically engineered pigs as tissue and organ donors for xenotransplantation has helped to address these hurdles. Although several preclinical trials have been conducted in nonhuman primates, some barriers still exist and demand further efforts. This review focuses on the recent advances and remaining challenges in organ and tissue xenotransplantation.

Sexual reproduction is prevalent across diverse taxa. However, sex-determination mechanisms are so diverse that even closely related species often differ in sex-determination systems. Teleost fish is a taxonomic group with frequent turnovers of sex-determining mechanisms and thus provides us with great opportunities to investigate the molecular and evolutionary mechanisms underlying the turnover of sex-determining systems. Here, we compile recent studies on the diversity of sex-determination mechanisms in fish. We demonstrate that genes in the TGF-β signaling pathway are frequently used for master sex-determining (MSD) genes. MSD genes arise via two main mechanisms, duplication-and-transposition and allelic mutations, with a few exceptions. We also demonstrate that temperature influences sex determination in many fish species, even those with sex chromosomes, with higher temperatures inducing differentiation into males in most cases. Finally, we review theoretical models for the turnover of sex-determining mechanisms and discuss what questions remain elusive.

Cloning as it relates to the animal kingdom generally refers to the production of genetically identical individuals. Because cloning is increasingly the subject of renewed attention as a tool for rescuing endangered or extinct species, it seems timely to dissect the role of the numerous reproductive techniques encompassed by this term in animal species conservation. Although cloning is typically associated with somatic cell nuclear transfer, the recent advent of additional techniques that allow genome replication without genetic recombination demands that the use of induced pluripotent stem cells to generate gametes or embryos, as well as older methods such as embryo splitting, all be included in this discussion. Additionally, the phenomenon of natural cloning (e.g., a subset of fish, birds, invertebrates, and reptilian species that reproduce via parthenogenesis) must also be pointed out. Beyond the biology of these techniques are practical considerations and the ethics of using cloning and associated procedures in endangered or extinct species. All of these must be examined in concert to determine whether cloning has a place in species conservation. Therefore, we synthesize progress in cloning and associated techniques and dissect the practical and ethical aspects of these methods as they pertain to endangered species conservation.

Maintenance of genetic diversity in marine fishes targeted by commercial fishing is a grand challenge for the future. Most of these species are abundant and therefore important for marine ecosystems and food security. Here, we present a road map of how population genomics can promote sustainable fisheries. In these species, the development of reference genomes and whole genome sequencing is key, because genetic differentiation at neutral loci is usually low due to large population sizes and gene flow. First, baseline allele frequencies representing genetically differentiated populations within species must be established. These can then be used to accurately determine the composition of mixed samples, forming the basis for population demographic analysis to inform sustainably set fish quotas. SNP-chip analysis is a cost-effective method for determining baseline allele frequencies and for population identification in mixed samples. Finally, we describe how genetic marker analysis can transform stock identification and management.

Advancing scientific discovery requires investigators to embrace research practices that increase transparency and disclosure about materials, methods, and outcomes. Several research advocacy and funding organizations have produced guidelines and recommended practices to enhance reproducibility through detailed and rigorous research approaches; however, confusion around vocabulary terms and a lack of adoption of suggested practices have stymied successful implementation. Although reproducibility of research findings cannot be guaranteed due to extensive inherent variables in attempts at experimental repetition, the scientific community can advocate for generalizability in the application of data outcomes to ensure a broad and effective impact on the comparison of animals to translation within human research. This report reviews suggestions, based upon work with National Institutes of Health advisory groups, for improving rigor and transparency in animal research through aspects of experimental design, statistical assessment, and reporting factors to advocate for generalizability in the application of comparative outcomes between animals and humans.