African wild dogs (Lycaon pictus) from the Kruger National Park, South Africa are currently not inbred but have low genomic diversity

MHC Diversity Across Time and Space

Most natural populations are genetically diverse. Understanding how diversity is maintained and distributed across time and space can provide insights into the potential for evolution and extinction of populations. Immunogenetic diversity aids individuals and populations in resisting infectious disease, with many studies linking resistance to genes encoding adaptive immune responses, such as the major histocompatibility complex (MHC) genes. The MHC is particularly important for advancing our understanding of local adaptive processes and host-parasite interactions. Here, we review the emerging work and theory exploring the geographic and temporal patterns of MHC diversity in the wild and how they are shaped by selective and demographic processes. We discuss patterns of variation along latitudinal and altitudinal gradients and place this in the context of Latitude Diversity Gradient and Central Marginal Theories. We emphasize how MHC diversity is often lower at the edges of species distributions, particularly in high-latitude and high-altitude regions. We also discuss MHC diversity in natural populations facing climate change. As climate change accelerates and emerging parasites spread, reduced immunogenetic diversity could severely threaten wildlife populations, compromising their resilience and long-term survival. We propose that including immunogenetic diversity into a larger database of environmental and parasite data would allow biologists to test hypotheses regarding host-parasite coevolution and develop effective measures for conservation.

Harnessing the omics revolution to address the global biodiversity crisis

Human disturbances are altering global biodiversity in unprecedented ways. We identify three fundamental challenges underpinning our understanding of global biodiversity (namely discovery, loss, and preservation), and discuss how the omics revolution (e.g. genomics, transcriptomics, proteomics, metabolomics, and meta-omics) can help address these challenges. We also discuss how omics tools can illuminate the major drivers of biodiversity loss, including invasive species, pollution, urbanization, overexploitation, and climate change, with a special focus on highly diverse tropical environments. Although omics tools are transforming the traditional toolkit of biodiversity research, their application to addressing the current biodiversity crisis remains limited and may not suffice to offset current rates of biodiversity loss. Despite technical and logistical challenges, omics tools need to be fully integrated into global biodiversity research, and better strategies are needed to improve their translation into biodiversity policy and practice. It is also important to recognize that although the omics revolution can be considered the biologist's dream, socioeconomic disparity limits their application in biodiversity research.

Evidence, Challenges, and Knowledge Gaps Regarding Latent Tuberculosis in Animals

Mycobacterium bovis and other Mycobacterium tuberculosis complex (MTBC) pathogens that cause domestic animal and wildlife tuberculosis have received considerably less attention than M. tuberculosis, the primary cause of human tuberculosis (TB). Human TB studies have shown that different stages of infection can exist, driven by host-pathogen interactions. This results in the emergence of heterogeneous subpopulations of mycobacteria in different phenotypic states, which range from actively replicating (AR) cells to viable but slowly or non-replicating (VBNR), viable but non-culturable (VBNC), and dormant mycobacteria. The VBNR, VBNC, and dormant subpopulations are believed to underlie latent tuberculosis (LTB) in humans; however, it is unclear if a similar phenomenon could be happening in animals. This review discusses the evidence, challenges, and knowledge gaps regarding LTB in animals, and possible host-pathogen differences in the MTBC strains M. tuberculosis and M. bovis during infection. We further consider models that might be adapted from human TB research to investigate how the different phenotypic states of bacteria could influence TB stages in animals. In addition, we explore potential host biomarkers and mycobacterial changes in the DosR regulon, transcriptional sigma factors, and resuscitation-promoting factors that may influence the development of LTB.