Spalax Research Articles

Altitude shapes gut microbiome composition accounting for diet, thyroid hormone levels, and host genetics in a subterranean blind mole rat.

The animal gut microbiome acts as a crucial link between the host and its environment, playing a vital role in digestion, metabolism, physiology, and fitness. Using 16S rRNA metabarcoding, we investigated the effect of altitude on the microbiome composition of Anatolian Blind Mole Rats (Nannospalax xanthodon) across six locations and three altitudinal groups. We also factored in the host diet, as well as host microsatellite genotypes and thyroid hormone levels. The altitude had a major effect on microbiome composition, with notable differences in the relative abundance of several bacterial taxa across elevations. Contrary to prior research, we found no significant difference in strictly anaerobic bacteria abundance among altitudinal groups, though facultatively anaerobic bacteria were more prevalent at higher altitudes. Microbiome alpha diversity peaked at mid-altitude, comprising elements from both low and high elevations. The beta diversity showed significant association with the altitude. Altitude had a significant effect on the diet composition but not on its alpha diversity. No distinct altitude-related genetic structure was evident among the host populations, and no correlation was revealed between the host genetic relatedness and microbiome composition nor between the host microbiome and the diet. Free thyroxine (FT4) levels increased almost linearly with the altitude but none of the bacterial ASVs were found to be specifically associated with hormone levels. Total thyroxine (TT4) levels correlated positively with microbiome diversity. Although we detected correlation between certain components of the thyroid hormone levels and the microbiome beta diversity, the pattern of their relationship remains inconclusive.

Targeting Mitochondrial Networks of Hypoxia Resistance in Long-Lived Blind Mole Rats

Targeting Mitochondrial Networks of Hypoxia Resistance in Long-Lived Blind Mole Rats

Habitat Suitability Assessment for Two Burrowing Rodents on the Island of Lesvos: A Niche-Based Approach.

We conducted a habitat suitability assessment for two burrowing rodents, Anatolian or Nehring's blind mole rat (Nannospalax xanthodon) and Harting's vole (Microtus hartingi), on the island of Lesvos using a niche-based approach. We collected data on the presence of the two species across the island and selected several environmental variables, including land cover, geology, and habitat topography, to assess their influence on habitat suitability. We used the Maxent species distribution modelling algorithm to predict suitable habitats. The results showed that both species preferred habitats with low slopes and specific geological substrates, i.e., alluvial deposits and volcanic rocks. M. hartingi showed a preference for open habitats such as saltmarshes and non-irrigated arable land, while N. xanthodon preferred non-irrigated arable land, pastures, and discontinuous urban fabric. The model predicted a wider area of suitable habitats for Microtus hartingi compared to N. xanthodon. Interestingly, the two species are absent from the southeastern part of the island despite our model predicting high suitability; this indicates that a natural barrier of hilly terrain, extensive pine forests, and limestone rock formations may exist that impedes dispersal. Our study provides valuable insights into the habitat preferences of these two burrowing rodents on the island of Lesvos, which can inform biodiversity conservation and ecosystem management strategies.

Splice Variant of Spalax Heparanase Skipping Exon 12.

The subterranean blind mole rat, Spalax, has evolved significantly over 47 million years to thrive in its underground habitat. A key enzyme in this adaptation is heparanase, which degrades heparan sulfate (HS) in the extracellular matrix (ECM), facilitating angiogenesis and releasing growth factors for endothelial cells. Spalax heparanase has various splice variants influencing tumor growth and metastasis differently. We report a novel splice variant from a hypoxia-exposed kidney sample resulting from exon 12 skipping. This variant maintains the translation frame but lacks enzymatic activity, offering insights into Spalax's unique adaptations.

Abstract 4890: In silico study of enzymes involved in heparan sulfate catabolic process in cancer resistant mammals

Abstract Some mammals such as elephants, bats, whales, and blind mole rats (Spalax) are resistant to cancer. One of the cancer protective mechanisms present in such species includes a reduced degradation of heparan sulfate (HS), an important component of the extracellular matrix (ECM), present in Spalax. Such effect occurs due to a splicing variant of heparanase, called variant 36, that lacks enzymatic activity. Consequently, both HS and ECM are very stable in Spalax’s tissues. If HS is stabilized, in cancer resistant mammals, due to the decrease of heparanase or other enzymes involved in HS catabolic process is unknown. We studied total of 9 enzymes (HPSE2, GusB, IDUA, IDS, NAGLU, SGSH, GNS, Sulf-2, HGSNAT) that regulate HS catabolism and homologs in 9 mammals. Multiple sequence alignments were done by MEGA to identify substitutions present in cancer resistant species in comparison with cancer susceptible animals. Such amino acid variants were further analyzed and both their energy stability and their functional effects were predicted by using online in silico tools including MAESTROweb, Condel, PANTHER, REVEL, and CADD. Finally, homologs with deleterious predicted variants were modelled with SWISSMODEL and their 3D structures were analyzed with Pymol and ChimeraX to identify structural features likely related to its loss of function. We found two loss of function missense variants, K264Q and W626L, in Alpha-L-iduronidase (IDUA) of Spalax. In addition, most of Brandt's bat enzymes and the N-sulphoglucosamine sulphohydrolase (SGSH) of the bowhead whale were very energy destabilizing enzymes with positive and higher ΔΔG values compared to human homologs. In the other hand, although some catalytic residues in the study enzymes are conserved in cancer resistant animals, their spatial arrangement and conformation in the 3D structure are different compared to human homologs, including E182 of IDUA which is one of the catalytic residues. In general, the secondary structure is conserved across the 9 enzymes studied but some differences were observed in cancer resistant animals including one of the beta strands near the catalytic domain in human and mice IDUA that appears as a loop in Spalax. In summary, HS stabilization could raise in cancer resistant mammals through the existence of lack of enzymatic activity not only in heparanase but also in other enzymes that participate in HS catabolic process, via a set of loss of function variants and changes in secondary and tertiary structure as well as a reduction of energy stabilization. More interestingly, such mechanism could be present in other cancer resistant mammals such as bats and bowhead whales. This study demonstrates that computational approaches are useful to study biological mechanisms of cancer resistance present in some mammals. This knowledge could be translated to humans and HS catabolic process could offer a new source of therapeutic anticancer targets. Citation Format: Fabrizio Oliveri Payet, Claudia Machicado Rivero. In silico study of enzymes involved in heparan sulfate catabolic process in cancer resistant mammals [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4890.

A Cryptic Subterranean Mammal Species, the Lesser Blind Mole Rat (Nannospalax leucodon syrmiensis)-Retreated but Not Extinct.

Blind mole rats (genus Nannospalax) attract a great deal of attention because of their cancer resistance and longevity. Due to the high rate of chromosome rearrangements, 74 Nannospalax chromosomal forms have been discovered. The convergence of their external morphology complicates their taxonomy, and many cryptic species remain unrecognized. Thus, the European N. leucodon supersp. is listed in the IUCN Red List of Threatened Species with "Data Deficient" status. It is crucial for the conservation of biodiversity to clarify its taxonomy, to recognize each cryptic species, and assign to them the correct conservation status. Of the more than 20 chromosomal forms described within N. leucodon, five cryptic species occur in Serbia. The most threatened among them-N. l. syrmiensis, described and named 50 years ago in the regions of Srem, Belgrade and Mačva-has been declared extinct in the literature, which may have negative consequences for the conservation of wildlife genetic diversity. Through five years of fieldwork and comparison of 16SrRNA and MT-CYTB gene segments between old, archived teeth and recently collected material, we show that N. l. syrmiensis is not extinct. However, its habitat has been fragmented and reduced, owing primarily to anthropogenic impact. Therefore, detailed surveillance, population-structure studies, risk assessment, and appropriate conservation measures are needed.

Conservation status of the blind mole rat populations in Hungary (Rodentia: Spalacinae: Nannospalax) revisited.

Regular reviews of long-term research and conservation programs are useful sources of information for future directions in science and for the assessment of current conservation status of taxa. In this paper, we compiled all available data from the last 10years related to Hungarian blind mole rat populations and assessed this information according to the following main themes: systematics, distribution and threats, and conservation actions. Based on the most recent information, national and global risk assessments are provided for the three species of Nannospalax (N. montanosyrmiensis, N. hungaricus and N. syrmiensis), currently accepted as part of the Hungarian fauna.

Evolutionary history and systematics of European blind mole rats (Rodentia: Spalacidae: Nannospalax): Multilocus phylogeny and species delimitation in a puzzling group

Species delimitation is a powerful approach to assist taxonomic decisions in challenging taxa where species boundaries are hard to establish. European taxa of the blind mole rats (genus Nannospalax) display small morphological differences and complex chromosomal evolution at a shallow evolutionary divergence level. Previous analyses led to the recognition of 25 ‘forms’ in their distribution area. We provide a comprehensive framework to improve knowledge on the evolutionary history and revise the taxonomy of European blind mole rats based on samples from all but three of the 25 forms. We sequenced two nuclear-encoded genetic regions and the whole mitochondrial cytochrome b gene for phylogenetic tree reconstructions using concatenation and coalescence-based species-tree estimations. The phylogenetic analyses confirmed that Aegean N. insularis belongs to N. superspecies xanthodon, and that it represents the second known species of this superspecies in Europe. Mainland taxa reached Europe from Asia Minor in two colonisation events corresponding to two superspecies-level taxa: N. superspecies monticola (taxon established herewith) reached Europe c. 2.1 million years ago (Mya) and was followed by N. superspecies leucodon (re-defined herewith) c. 1.5 Mya. Species delimitation allowed the clarification of the taxonomic contents of the above superspecies. N. superspecies monticola contains three species geographically confined to the western periphery of the distribution of blind mole rats, whereas N. superspecies leucodon is more speciose with six species and several additional subspecies. The observed geographic pattern hints at a robust peripatric speciation process and rapid chromosomal evolution. The present treatment is thus regarded as the minimum taxonomic content of each lineage, which can be further refined based on other sources of information such as karyological traits, crossbreeding experiments, etc. The species delimitation models also allowed the recognition of a hitherto unnamed blind mole rat taxon from Albania, described here as a new subspecies.

Thermal biology in the Upper Galili Mountain blind mole rat (Nannospalax galili) and an overview of spalacine energetics

Several hundred mammalian species thrive in complex burrow systems, which protect them from climatic extremes and predation. At the same time, it is also a stressful environment due to low food supply, high humidity, and, in some cases, a hypoxic and hypercapnic atmosphere. To face such conditions, subterranean rodents have convergently evolved low basal metabolic rate, high minimal thermal conductance and low body temperature. Although these parameters have been intensively studied in the last decades, such information is far from being well-known in one of the most studied groups of subterranean rodents, the blind mole rats of the genus Nannospalax. The lack of information is particularly noticeable for parameters such as the upper critical temperature and the width of the thermoneutral zone.In our study, we analysed the energetics of the Upper Galilee Mountain blind mole rat Nannospalax galili and found its basal metabolic rate of 0.84 ± 0.10 mL O2×g−1 × h−1, thermoneutral zone between 28 and 35 °C, mean Tb within the zone of 36.3 ± 0.6 °C, and minimal thermal conductance equal to 0.082 mL O2×g−1 × h−1 × C−1. Nannospalax galili is a truly homeothermic rodent well adapted to face lower ambient temperatures, because its Tb was stable down to the lowest temperature measured (10 °C). At the same time, a relatively high basal metabolic rate and relatively low minimal thermal conductance for a subterranean rodent of such body mass, and the difficulty of surviving ambient temperatures slightly above upper critical temperature, indicates problems with sufficient heat dissipation at higher temperatures. This can easily lead to overheating, that is relevant mainly during the hot-dry season. These findings suggest that N. galili can be threatened by ongoing global climate change.

The microbiota of long-living and cancer-free blind mole rat $\textit{(Nannospalax xanthodon)}$ from the edge of its distribution in Northern Anatolia

The mammalian gut is colonized by microorganisms that affect development, immune system, energy metabolism, and reproduction. The majority of studies focused on laboratory or domestic animals in artificial setups, leaving the research focused on wild species underrepresented. The Anatolian Blind Molerat (hereafter ABMR), $\textit{Nannospalax xanthodon}$, is a subterranean rodent that receives much attention due to its unique traits, such as tolerance to extreme hypoxic stress, resistance to cancer, and longer lifespan compared to similarly sized rodents. In this study, we characterize the gut microbiota of ABMR from its northernmost geographic distribution using 16S rRNA metabarcoding and compare our results with the microbiome characteristics of a few other ABMR populations studied previously, as well as other rodent species. The 16S rRNA barcode dataset revealed that approximately 90% of the ABMR gut microbiota comprises Firmicutes and Bacteriodota bacterial phyla, typical of most mammals. In addition, the ABMR gut microbiota has a high abundance of performance- and longevity-linked bacterial families. Overall, our results generally align well with the previous studies on blind molerats and emphasize the importance of studying the microbiome of natural populations.

Investigation of Clock Gene Variations in Nannospalax Cytotypes

Blind mole rats (Nannospalax) are subterranean mammals noted for their longevity and cancerresistance. It is known that these animals' vestigial eyes, particularly the Harder gland around the eyes, maygenerate considerable amounts of melatonin. Furthermore, the melatonin production mechanism in thecircadian rhythm cycle of blind mole rats is regarded to be different from that of other living beings. Themelatonin and Clock genes are hypothesized to be linked to the formation, development, and spread ofcancer, but the researchers still cannot explain their extraordinary cancer resistance.In this study, we hypothesized that the melatonin production mechanism in the circadian rhythm cycle ofblind mole rats, which have been shown in the literature to be cancer-resistant, may differ from that of otherliving species due to the difference in their amino acid variations. Differences in the DNA of the Clockgenes (Cry1 and Per1) involved in melatonin biosynthesis in blind mole rats were studied compared toother model species (Spalax galili, Mus musculus, Heterocephalus glaber, Rattus norvegicus, and Homosapiens). As a result, while no variations were found in the Cry1 gene; only p.G7R variation was found inthe Per1 gene. The SNAP2 software had demonstrated that the human analogs of this variation harmfuleffects. It was suggested that more or full exon sites, more samples and genes should be studied to observemore variants in Nannospalax species. Thereby, the cancer resistance of blind mole rats may be explainedbetter by these variations and the functions of protein domains where these variants are located in.

Emergence of Maps in the Memories of Blind Navigation Agents

Decades of research into intelligent animal navigation posits that organisms build and maintain internal spatial representations (or maps) 1 of their environment, that enables the organism to determine and follow task-appropriate paths (Epstein, Patai, Julian, & Spiers, 2017; O'keefe & Nadel, 1978; Tollman, 1948). Hamsters, wolves, chimpanzees, and bats leverage prior exploration to determine and follow shortcuts they may never have taken before (Chapuis & Scardigli, 1993; Harten, Katz, Goldshtein, Handel, & Yovel, 2020; Menzel, 1973; Peters, 1976; Toledo et al., 2020). Even blind mole rats and animals rendered situationally-blind in dark environments demonstrate shortcut behaviors (Avni, Tzvaigrach, & Eilam, 2008; Kimchi, Etienne, & Terkel, 2004; Maaswinkel & Whishaw, 1999). Ants forage for food along meandering paths but take near-optimal return trips (Müller & Wehner, 1988), though there is some controversy about whether insects like ants and bees are capable of forming maps (Cheung et al., 2014; Cruse & Wehner, 2011).

Damage-Free Shortening of Telomeres Is a Potential Strategy Supporting Blind Mole-Rat Longevity.

Telomere shortening or loss of shelterin components activates DNA damage response (DDR) pathways, leading to a replicative senescence that is usually coupled with a senescence-associated secretory phenotype (SASP). Recent studies suggested that telomere aberration that activates DDR may occur, irrespective of telomere length or loss of shelterin complex. The blind mole-rat (Spalax) is a subterranean rodent with exceptional longevity, and its cells demonstrate an uncoupling of senescence and SASP inflammatory components. Herein, we evaluated Spalax relative telomere length, telomerase activity, and shelterin expression, along with telomere-associated DNA damage foci (TAFs) levels with cell passage. We show that telomeres shorten in Spalax fibroblasts similar to the process in rats, and that the telomerase activity is lower. Moreover, we found lower DNA damage foci at the telomeres and a decline in the mRNA expression of two shelterin proteins, known as ATM/ATR repressors. Although additional studies are required for understanding the underling mechanism, our present results imply that Spalax genome protection strategies include effective telomere maintenance, preventing early cellular senescence induced by persistent DDR, thereby contributing to its longevity and healthy aging.

Senescent Secretome of Blind Mole Rat Spalax Inhibits Malignant Behavior of Human Breast Cancer Cells Triggering Bystander Senescence and Targeting Inflammatory Response

Subterranean blind mole rat, Spalax, has developed strategies to withstand cancer by maintaining genome stability and suppressing the inflammatory response. Spalax cells undergo senescence without the acquisition of senescence-associated secretory phenotype (SASP) in its canonical form, namely, it lacks the main inflammatory mediators. Since senescence can propagate through paracrine factors, we hypothesize that conditioned medium (CM) from senescent Spalax fibroblasts can transmit the senescent phenotype to cancer cells without inducing an inflammatory response, thereby suppressing malignant behavior. To address this issue, we investigated the effect of CMs of Spalax senescent fibroblasts on the proliferation, migration, and secretory profile in MDA-MB-231 and MCF-7 human breast cancer cells. The results suggest that Spalax CM induced senescence in cancer cells, as evidenced by increased senescence-associated beta-galactosidase (SA-β-Gal) activity, growth suppression and overexpression of senescence-related p53/p21 genes. Contemporaneously, Spalax CM suppressed the secretion of the main inflammatory factors in cancer cells and decreased their migration. In contrast, human CM, while causing a slight increase in SA-β-Gal activity in MDA-MB-231 cells, did not decrease proliferation, inflammatory response, and cancer cell migration. Dysregulation of IL-1α under the influence of Spalax CM, especially the decrease in the level of membrane-bound IL1-α, plays an important role in suppressing inflammatory secretion in cancer cells, which in turn leads to inhibition of cancer cell migration. Overcoming of SASP in tumor cells in response to paracrine factors of senescent microenvironment or anti-cancer drugs represents a promising senotherapeutic strategy in cancer treatment.

The Mystery of Cancer Resistance: A Revelation Within Nature.

Cancer, a disease due to uncontrolled cell proliferation is as ancient as multicellular organisms. A 255-million-years-old fossilized forerunner mammal gorgonopsian is probably the oldest evidence of cancer, to date. Cancer seems to have evolved by adapting to the microenvironment occupied by immune sentinel, modulating the cellular behavior from cytotoxic to regulatory, acquiring resistance to chemotherapy and surviving hypoxia. The interaction of genes with environmental carcinogens is central to cancer onset, seen as a spectrum of cancer susceptibility among human population. Cancer occurs in life forms other than human also, although their exposure to environmental carcinogens can be different. Role of genetic etiology in cancer in multiple species can be interesting with regard to not only cancer susceptibility, but also genetic conservation and adaptation in speciation. The widely used model organisms for cancer research are mouse and rat which are short-lived and reproduce rapidly. Research in these cancer prone animal models has been valuable as these have led to cancer therapy. However, another rewarding area of cancer research can be the cancer-resistant animal species. The Peto's paradox and G-value paradox are evident when natural cancer resistance is observed in large mammals, like elephant and whale, small rodents viz. Naked Mole Rat and Blind Mole Rat, and Bat. The cancer resistance remains to be explored in other small or large and long-living animals like giraffe, camel, rhinoceros, water buffalo, Indian bison, Shire horse, polar bear, manatee, elephant seal, walrus, hippopotamus, turtle and tortoise, sloth, and squirrel. Indeed, understanding the molecular mechanisms of avoiding neoplastic transformation across various life forms can be potentially having translational value for human cancer management. Adapted and Modified from (Hanahan and Weinberg 2011).

Мониторинг солнечного орла в национальном парке «Хвалынский» (Саратовская область, Россия)

Мониторинг солнечного орла в национальном парке «Хвалынский» (Саратовская область, Россия)

An examination of blind mole-rat (Nannospalax xanthodon) brain, cerebellum, and spinal cord tissues: A histological and stereological study

The purpose of this study was to perform a histological examination of blind mole-rat (Nannospalax xanthodon) brain, cerebellum, and spinal cord tissues. Six blind mole-rats were caught in a natural environment, anesthetized with ether, and sacrificed. Brain, cerebellum, and spinal cord tissues were then removed. All tissues were kept in 10% formaldehyde for one week, at the end of which they were subjected to routine histological procedures and embedded in blocks. Five micron-thick sections were taken from the blocks (5 and 15 micron thick from spinal cord tissues). All sections were then stained with hematoxylin-eosin, Cresyl Violet, and DAPI. These sections were then evaluated under light and fluorescent microscopes. The blind mole-rats weighed 201.3 ± 61 g, the brains and cerebella weighed 1.8 ± 0.3 mg and 0.32 ± 0.05 mg, respectively, and the brain, cerebellum, and spinal cord volumes were 1.49±0.46 ml, 0.33± 0.08 ml, and 2.53± 0.19 µm3, respectively. No histological variation was observed in the brain or cerebellum tissues. However, examination of the spinal cord tissue revealed differences compared to humans and other rodents. The spinal cord exhibited a segmented, lobulated appearance, each lobe itself exhibiting the characteristics of a small spinal cord. No butterfly appearance was observed, and white and gray matter transitions were irregular, with less white and more gray matter. The location of the anterior and posterior horns was unclear. The motor neuron cells were also small in size. No significant variations were observed at nuclear organization (DAPI signals) between any tissues. In conclusion, the blind mole-rats were normal in weight, increased brain and cerebellum tissue weight and volumes were observed, while a decrease was determined in spinal cord tissue volumes. The brain and cerebellum were normal at histological examination, while structural differences were detected in the spinal cord.

Patch and matrix characteristics determine the outcome of ecosystem engineering by mole rats in dry grasslands.

Burrowing mammals are important ecosystem engineers, especially in open ecosystems where they create patches that differ from the surrounding matrix in their structure or ecosystem functions. We evaluated the fine-scale effects of a subterranean ecosystem engineer, the Lesser blind mole rat on the vegetation composition of sandy dry grasslands in Hungary. In this model system we tested whether the characteristics of the patch (mound size) and the matrix (total vegetation cover in the undisturbed grassland) influence the structural and functional contrasts between the mounds and the undisturbed grasslands. We sampled the vegetation of 80 mounds and 80 undisturbed grassland plots in four sites, where we recorded the total vegetation cover, and the occurrence and cover of each vascular plant species. We used two proxies to characterise the patches (mounds) and the matrix (undisturbed grassland): we measured the perimeter of the mounds and estimated the total vegetation cover of the undisturbed grasslands. First, we compared the vegetation characteristics of the mounds and the surrounding grasslands with general linear models. Second, we characterised the contrasts between the mounds and the undisturbed grassland by relative response indices (RRIs) of the vegetation characteristics studied in the first step. Species composition of the vegetation of the mounds and undisturbed grasslands was well separated in three out of the four study sites. Mounds were characterised by lower vegetation cover, lower cover of perennial graminoids, and higher diversity, and evenness compared to undisturbed grasslands. The contrast in vegetation cover between mounds and undisturbed grasslands increased with decreasing patch size. Increasing vegetation cover in the matrix grasslands increased the contrasts between the mounds and undisturbed grasslands in terms of total cover, perennial graminoid cover, diversity, and evenness. Our results suggest that mole rat mounds provide improved establishment conditions for subordinate species, because they are larger than other types of natural gaps and are characterised by less intense belowground competition. The ecosystem engineering effect, i.e., the contrast between the patches and the matrix was the largest in the more closed grasslands.

Beyond the Lab: What We Can Learn about Cancer from Wild and Domestic Animals.

Cancer research has benefited immensely from the use of animal models. Several genetic tools accessible in rodent models have provided valuable insight into cellular and molecular mechanisms linked to cancer development or metastasis and various lines are available. However, at the same time, it is important to accompany these findings with those from alternative or non-model animals to offer new perspectives into the understanding of tumor development, prevention, and treatment. In this review, we first discuss animals characterized by little or no tumor development. Cancer incidence in small animals, such as the naked mole rat, blind mole rat and bats have been reported as almost negligible and tumor development may be inhibited by increased defense and repair mechanisms, altered cell cycle signaling and reduced rates of cell migration to avoid tumor microenvironments. On the other end of the size spectrum, large animals such as elephants and whales also appear to have low overall cancer rates, possibly due to gene replicates that are involved in apoptosis and therefore can inhibit uncontrolled cell cycle progression. While it is important to determine the mechanisms that lead to cancer protection in these animals, we can also take advantage of other animals that are highly susceptible to cancer, especially those which develop tumors similar to humans, such as carnivores or poultry. The use of such animals does not require the transplantation of malignant cancer cells or use of oncogenic substances as they spontaneously develop tumors of similar presentation and pathophysiology to those found in humans. For example, some tumor suppressor genes are highly conserved between humans and domestic species, and various tumors develop in similar ways or because of a common environment. These animals are therefore of great interest for broadening perspectives and techniques and for gathering information on the tumor mechanisms of certain types of cancer. Here we present a detailed review of alternative and/or non-model vertebrates, that can be used at different levels of cancer research to open new perspectives and fields of action.

Host diet shapes functionally differentiated gut microbiomes in sympatric speciation of blind mole rats in Upper Galilee, Israel.

The gut microbiome is important for host nutrient metabolism and ecological adaptation. However, how the gut microbiome is affected by host phylogeny, ecology and diet during sympatric speciation remain unclear. Here, we compare and contrast the gut microbiome of two sympatric blind mole rat species and correlate them with their corresponding host phylogeny, ecology soil metagenomes, and diet to determine how these factors may influence their gut microbiome. Our results indicate that within the host microbiome there is no significant difference in community composition, but the functions between the two sympatric species populations vary significantly. No significant correlations were found between the gut microbiome differentiation and their corresponding ecological soil metagenomes and host phylogeny. Functional enrichment analysis suggests that the host diets may account for the functional divergence of the gut microbiome. Our results will help us understand how the gut microbiome changes with corresponding ecological dietary factors in sympatric speciation of blind subterranean mole rats.