-
Science (New York, N.Y.) Nov 2023Sexually dimorphic traits are common among mammals and are specified during development through the deployment of sex-specific genetic programs. Because little is known...
Sexually dimorphic traits are common among mammals and are specified during development through the deployment of sex-specific genetic programs. Because little is known about these programs, we investigated them using a resource of gene expression profiles in males and females throughout the development of five organs in five mammals (human, mouse, rat, rabbit, and opossum) and a bird (chicken). We found that sex-biased gene expression varied considerably across organs and species and was often cell-type specific. Sex differences increased abruptly around sexual maturity instead of increasing gradually during organ development. Finally, sex-biased gene expression evolved rapidly at the gene level, with differences between organs in the evolutionary mechanisms used, but more slowly at the cellular level, with the same cell types being sexually dimorphic across species.
Topics: Animals; Female; Humans; Male; Mice; Rabbits; Rats; Chickens; Evolution, Molecular; Gene Expression Regulation, Developmental; Mammals; RNA-Seq; Sex Characteristics; Transcriptome; Organogenesis
PubMed: 37917687
DOI: 10.1126/science.adf1046 -
Emerging Infectious Diseases Mar 2024We reviewed information about mammals naturally infected by highly pathogenic avian influenza A virus subtype H5N1 during 2 periods: the current panzootic (2020-2023)... (Review)
Review
We reviewed information about mammals naturally infected by highly pathogenic avian influenza A virus subtype H5N1 during 2 periods: the current panzootic (2020-2023) and previous waves of infection (2003-2019). In the current panzootic, 26 countries have reported >48 mammal species infected by H5N1 virus; in some cases, the virus has affected thousands of individual animals. The geographic area and the number of species affected by the current event are considerably larger than in previous waves of infection. The most plausible source of mammal infection in both periods appears to be close contact with infected birds, including their ingestion. Some studies, especially in the current panzootic, suggest that mammal-to-mammal transmission might be responsible for some infections; some mutations found could help this avian pathogen replicate in mammals. H5N1 virus may be changing and adapting to infect mammals. Continuous surveillance is essential to mitigate the risk for a global pandemic.
Topics: Animals; Influenza A Virus, H5N1 Subtype; Influenza in Birds; Influenza A virus; Mammals; Mutation
PubMed: 38407173
DOI: 10.3201/eid3003.231098 -
Emerging Infectious Diseases Jul 2024We report highly pathogenic avian influenza A(H5N1) virus in dairy cattle and cats in Kansas and Texas, United States, which reflects the continued spread of clade...
We report highly pathogenic avian influenza A(H5N1) virus in dairy cattle and cats in Kansas and Texas, United States, which reflects the continued spread of clade 2.3.4.4b viruses that entered the country in late 2021. Infected cattle experienced nonspecific illness, reduced feed intake and rumination, and an abrupt drop in milk production, but fatal systemic influenza infection developed in domestic cats fed raw (unpasteurized) colostrum and milk from affected cows. Cow-to-cow transmission appears to have occurred because infections were observed in cattle on Michigan, Idaho, and Ohio farms where avian influenza virus-infected cows were transported. Although the US Food and Drug Administration has indicated the commercial milk supply remains safe, the detection of influenza virus in unpasteurized bovine milk is a concern because of potential cross-species transmission. Continued surveillance of highly pathogenic avian influenza viruses in domestic production animals is needed to prevent cross-species and mammal-to-mammal transmission.
Topics: Animals; Cats; Cattle; Cat Diseases; Cattle Diseases; Orthomyxoviridae Infections; Influenza A Virus, H5N1 Subtype; United States; Influenza in Birds; Milk; Female
PubMed: 38683888
DOI: 10.3201/eid3007.240508 -
ELife Nov 2023A new computational tool provides insights into the structure of the cerebellum in mammals.
A new computational tool provides insights into the structure of the cerebellum in mammals.
Topics: Animals; Cerebellum; Mammals
PubMed: 37943162
DOI: 10.7554/eLife.93122 -
Cells & Development Sep 2023The testis is a key male reproductive organ that produces gametes through the process of spermatogenesis. Testis morphologies, sperm phenotypes, and the process of... (Review)
Review
The testis is a key male reproductive organ that produces gametes through the process of spermatogenesis. Testis morphologies, sperm phenotypes, and the process of spermatogenesis evolve rapidly in mammals, presumably due to the evolutionary pressure on males to give rise to their own offspring. Here, we review studies illuminating the molecular evolution of the testis, in particular large-scale transcriptomic studies, which were based on bulk tissue samples and, more recently, individual cells. Together with various genomic and epigenomic data, these studies have unveiled the cellular source, molecular mechanisms, and evolutionary forces that underlie the rapid phenotypic evolution of the testis. They also revealed shared (ancestral) and species-specific spermatogenic gene expression programs. The insights and available data that have accumulated also provide a valuable resource for the investigation and treatment of male fertility disorders - a dramatically increasing problem in modern industrial societies.
Topics: Animals; Male; Semen; Spermatogenesis; Testis; Evolution, Molecular; Mammals
PubMed: 37336426
DOI: 10.1016/j.cdev.2023.203865 -
Biological Chemistry Oct 2023Mammalian genomes are extensively transcribed, producing a large number of coding and non-coding transcripts. A large fraction of the nuclear RNAs is physically... (Review)
Review
Mammalian genomes are extensively transcribed, producing a large number of coding and non-coding transcripts. A large fraction of the nuclear RNAs is physically associated with chromatin, functioning in gene activation and silencing, shaping higher-order genome organisation, such as involvement in long-range enhancer-promoter interactions, transcription hubs, heterochromatin, nuclear bodies and phase transitions. Different mechanisms allow the tethering of these chromatin-associated RNAs (caRNA) to chromosomes, including RNA binding proteins, the RNA polymerases and R-loops. In this review, we focus on the sequence-specific targeting of RNA to DNA by forming triple helical structures and describe its interplay with chromatin. It turns out that nucleosome positioning at triple helix target sites and the nucleosome itself are essential factors in determining the formation and stability of triple helices. The histone H3-tail plays a critical role in triple helix stabilisation, and the role of its epigenetic modifications in this process is discussed.
Topics: Animals; Chromatin; Nucleosomes; Binding Sites; Histones; DNA; RNA; Mammals
PubMed: 37506218
DOI: 10.1515/hsz-2023-0189 -
Nephrology, Dialysis, Transplantation :... Jan 2024Phosphorus is an essential mineral that is, in the form of inorganic phosphate (Pi), required for building cell membranes, DNA and RNA molecules, energy metabolism,... (Review)
Review
Phosphorus is an essential mineral that is, in the form of inorganic phosphate (Pi), required for building cell membranes, DNA and RNA molecules, energy metabolism, signal transduction and pH buffering. In bone, Pi is essential for bone stability in the form of apatite. Intestinal absorption of dietary Pi depends on its bioavailability and has two distinct modes of active transcellular and passive paracellular absorption. Active transport is transporter mediated and partly regulated, while passive absorption depends mostly on bioavailability. Renal excretion controls systemic Pi levels, depends on transporters in the proximal tubule and is highly regulated. Deposition and release of Pi into and from soft tissues and bone has to be tightly controlled. The endocrine network coordinating intestinal absorption, renal excretion and bone turnover integrates dietary intake and metabolic requirements with renal excretion and is critical for bone stability and cardiovascular health during states of hypophosphataemia or hyperphosphataemia as evident from inborn or acquired diseases. This review provides an integrated overview of the biology of phosphate and Pi in mammals.
Topics: Animals; Humans; Phosphates; Phosphorus; Intestinal Absorption; Hyperphosphatemia; Minerals; Mammals
PubMed: 37660247
DOI: 10.1093/ndt/gfad188 -
Comprehensive Psychoneuroendocrinology Nov 2023Although there is a consistent literature documenting that vagal cardioinhibitory pathways support homeostatic functions, another less frequently cited literature... (Review)
Review
Although there is a consistent literature documenting that vagal cardioinhibitory pathways support homeostatic functions, another less frequently cited literature implicates vagal cardioinhibitory pathways in compromises to survival in humans and other mammals. The latter is usually associated with threat reactions, chronic stress, and potentially lethal clinical conditions such as hypoxia. Solving this 'vagal paradox' in studies conducted in the neonatal intensive care unit served as the motivator for the Polyvagal Theory (PVT). The paradox is resolved when the different functions of vagal cardioinhibitory fibers originating in two anatomically distinguishable brainstem areas are recognized. One pathway originates in a dorsal area known as the dorsal motor nucleus of the vagus and the other in a ventral area of the brainstem known as nucleus ambiguus. Unlike mammals, in all ancestral vertebrates from which mammals evolved, cardioinhibitory vagal fibers primarily originate in the dorsal motor nucleus of the vagus. Thus, in mammals the vagus nerve is 'poly' vagal because it contains two distinct efferent pathways. Developmental and evolutionary biology identify a ventral migration of vagal cardioinhibitory fibers that culminate in an integrated circuit that has been labeled the ventral vagal complex. This complex consists of the interneuronal communication of the ventral vagus with the source nuclei involved in regulating the striated muscles of the head and face via special visceral efferent pathways. This integrated system enables the coordination of vagal regulation of the heart with sucking, swallowing, breathing, and vocalizing and forms the basis of a social engagement system that allows sociality to be a potent neuromodulator resulting in calm states that promote homeostatic function. These biobehavioral features, dependent on the maturation of the ventral vagal complex, can be compromised in preterm infants. Developmental biology informs us that in the immature mammal (e.g., fetus, preterm infant) the ventral vagus is not fully functional and myelinization is not complete; this neuroanatomical profile may potentiate the impact of vagal cardioinhibitory pathways originating in the dorsal motor nucleus of the vagus. This vulnerability is confirmed clinically in the life-threatening reactions of apnea and bradycardia in human preterm newborns, which are hypothetically mediated through chronotropic dorsal vagal pathways. Neuroanatomical research documents that the distribution of cardioinhibitory neurons representing these two distinct vagal source nuclei varies among mammals and changes during early development. By explaining the solution of the 'vagal paradox' in the preterm human, the paper highlights the functional cardioinhibitory functions of the two vagal source nuclei and provides the scientific foundation for the testing of hypotheses generated by PVT.
PubMed: 38108034
DOI: 10.1016/j.cpnec.2023.100200 -
Viruses Jan 2024Nipah virus (NiV) is an emerging zoonotic paramyxovirus to which is attributed numerous high mortality outbreaks in South and South-East Asia; Bangladesh's Nipah belt... (Review)
Review
Nipah virus (NiV) is an emerging zoonotic paramyxovirus to which is attributed numerous high mortality outbreaks in South and South-East Asia; Bangladesh's Nipah belt accounts for the vast majority of human outbreaks, reporting regular viral emergency events. The natural reservoir of NiV is the Pteropus bat species, which covers a wide geographical distribution extending over Asia, Oceania, and Africa. Occasionally, human outbreaks have required the presence of an intermediate amplification mammal host between bat and humans. However, in Bangladesh, the viral transmission occurs directly from bat to human mainly by ingestion of contaminated fresh date palm sap. Human infection manifests as a rapidly progressive encephalitis accounting for extremely high mortality rates. Despite that, no therapeutic agents or vaccines have been approved for human use. An updated review of the main NiV infection determinants and current potential therapeutic and preventive strategies is exposed.
Topics: Animals; Humans; Nipah Virus; Chiroptera; Disease Outbreaks; Asia; Bangladesh; Henipavirus Infections
PubMed: 38399954
DOI: 10.3390/v16020179