Genetic Connectivity Research Articles

Evolución de la biodiversidad amazónica: una revisión

ABSTRACT Amazonia (defined herein as the Amazon basin) is home to the greatest concentration of biodiversity on Earth, providing unique genetic resources and ecological functions that contribute to ecosystem services globally. The lengthy and complex evolutionary history of this region has produced heterogeneous landscapes and riverscapes at multiple scales, altered the geographic and genetic connections among populations, and impacted rates of adaptation, speciation, and extinction. In turn, ecologically diverse Amazonian biotas promoted further diversification, species coexistence, and coevolution, with biodiversity accumulating over tens of millions of years. Important events in Amazonian history included: (i) late Cretaceous and early Paleogene origin of major rainforest plant and animal groups; (ii) Eocene-Oligocene global cooling with rainforests contracting to tropical latitudes separating Atlantic coastal and Amazonian rainforests; (iii) Miocene uplift of central and northern Andes that separated Pacific coastal and Amazonian rainforests, spurred formation of mega-wetlands in the western Amazon, and contributed to the origin of the modern transcontinental Amazon River; (iv) late Neogene formation of the Panamanian Isthmus that facilitated the Great American Biotic Interchange; (v) Pleistocene climate oscillations followed by late Pleistocene-Holocene human colonization and megafaunal extinctions; and (vi) modern era of widespread anthropogenic deforestation, defaunation, and ecological transformations of regional landscapes and global climates. Amazonian conservation requires decade-scale investments into biodiversity documentation and monitoring to leverage existing scientific capacity, and strategic habitat planning to allow continuity of evolutionary and ecological processes now and into the future.

Pond area and availability safeguard amphibian genetic diversity across Iberia's largest protected wetland

Abstract Wetland ecosystems worldwide are threatened by habitat alteration, climate change and the introduction of invasive species, even within protected areas. Unravelling the reliance of sensitive wetland‐dwelling species, such as amphibians, on habitat characteristics is thus essential to identify conservation targets. Here we assess the distribution of genetic diversity of two strongly aquatic amphibians (Pelophylax perezi and Pleurodeles waltl) in association with habitat features across the most extensive, protected wetland of the Iberian Peninsula: Doñana National Park. Despite inhabiting a protected area free from anthropogenic barriers, the genetic diversity of P. perezi and P. waltl is not homogeneously distributed across the wetland, but instead concentrates in core areas, mainly in the northern zone. Both genetic diversity and connectivity (as opposed to genetic differentiation) showed significant positive associations with the area of the breeding sites and the flooded area surrounding the breeding sites within the dispersal potential of either species, that is nearby pond availability. Large water bodies connected to abundant temporary ponds are key for the maintenance of amphibian genetic diversity. Nevertheless, the core populations of our target species, which show markedly aquatic habits, are concentrated in areas colonised by invasive species, which could compromise their long‐term viability. Our results highlight that maintaining widely connected arrays of ponds of different hydroperiods, including large breeding sites free from invasive predators and competitors, is paramount for amphibian conservation in Mediterranean wetlands.

Machine learning provides insights for spatially explicit pest management strategies by integrating information on population connectivity and habitat use in a key agricultural pest.

Insect pests have garnered increasing interest because of anthropogenic global change, and their sustainable management requires knowledge of population habitat use and spread patterns. To enhance this knowledge for the prevalent tea pest Empoasca onukii, we utilized a random forest algorithm and a bivariate map to develop and integrate models of its habitat suitability and genetic connectivity across China. Our modeling revealed heterogeneous spatial patterns in suitability and connectivity despite the common key environmental predictor of isothermality. Analyses indicated that tea cultivation in areas surrounding the Tibetan Plateau and the southern tip of China may be at low risk of population outbreaks because of their predicted low suitability and connectivity. However, regions along the middle and lower reaches of the Yangtze River should consider the high abundance and high recolonization potential of E. onukii, and thus the importance of control measures. Our results also emphasized the need to prevent dispersal from outside regions in the areas north of the Yangtze River and highlighted the effectiveness of internal management efforts in southwestern China and along the southeastern coast. Further projections under future conditions suggested the potential for increased abundance and spread in regions north of the Yangtze River and the southern tip of China, and indicated the importance of long-term monitoring efforts in these areas. These findings highlighted the significance of combining information on habitat use and spread patterns for spatially explicit pest management planning. In addition, the approaches we used have potential applications in the management of other pest systems and the conservation of endangered biological resources. © 2024 Society of Chemical Industry.

LAW AND ECONOMICS IN SURROGACY MARKETS

The concept of reproductive justice can offer a framework for complex and nuanced analyses of surrogacy, taking into account the agency of surrogates and potential vulnerability of intended parents. When we define surrogacy contracts, we mean the situation in which the fertilized egg of a married couple is inserted into the uterus of a surrogate mother and carried to term by a woman who has no genetic connection with the fetus. Surrogacy contracts offer a way to supply a genetic connection that adoption contracts cannot provide. This paper argues that surrogacy with heavy regulation is a step forward into the future because it incorporates the best legal solution to custody disputes while also attaining the most economically efficient solution. This paper argues the same about surrogacy markets becoming a standard and prudent practice because calling babies a Pareto-efficient exchange that benefits everyone at the expense of no one. Surrogacy can be an excellent option for a set of biological parents who desire a child but cannot carry a pregnancy for health reasons, with potential framework for the psychological and sociological effects of mental health and abortion. The status of surrogacy agencies within the United States allows for heavy legal and economic regulation of surrogacy markets. When the law of contracts and property are incorporated into surrogacy markets, it is easier and more “efficient” for couples to make bargains with surrogate gestational carriers.

Applying geometric morphometrics in megalopa larval stages: relevance for species distribution and biological invasion studies

Abstract Larval morphology in brachyuran crabs is an essential trait defining survival in the planktonic environment. The present study describes the morphology (carapace and chelipeds) of megalopa larvae in three different species (Percnon gibbesi, Cronius ruber, and Achelous hastatus) using geometric morphometric analysis (gma). The study aim was to compare the observed body patterns at interspecific and intraspecific levels. The results showed a marked interspecific distinction of C. ruber larvae based on the rostral region of carapace and cheliped length. We relate these differences to advantages in life performance, as in other animal models, suggesting that larval morphology can be another factor contributing to the invasiveness of C. ruber. At intraspecific level, we found a high morphological similarity between two distant geographical locations, indicating strong genetic connectivity in the populations of P. gibbesi from the Canary Islands. Our findings advance the importance of larval morphology for species performance during the plankton phase that eventually can determine invasiveness in brachyuran crabs. We suggest future studies focusing on the inter-population comparisons of megalopa morphology at larger spatiotemporal scales.

Population genetics of caribou in the Alaska-Yukon border region: implications for designation of conservation units and small herd persistence

Better knowledge of genetic relationships between the Fortymile caribou herd and its neighbors is needed for conservation decision-making in Canada. Here, we contribute the first fine-scale analysis of genetic population structure in nine contiguous caribou herds at the geographic boundaries between Barren-ground and Northern Mountain caribou, and at the Alaska-Yukon border. Using pairwise differentiation metrics, STRUCTURE, and discriminant analysis of principal components (DAPC) to analyze 15 microsatellite loci in 379 caribou, we found complex patterns of genetic differentiation. The Fortymile was the only herd assigned to more than one genetic cluster, indicative of its history as a larger herd whose range expansions and gene flow to other herds were likely important to maintaining diversity across a functioning genetic metapopulation. Some small herds (Chisana, Klaza, and White Mountains) were genetically distinct, while others (Hart River, Clear Creek, Mentasta) exhibited little differentiation from herds they occasionally overlap, including herds assigned to different conservation units (DUs). This genetic connectivity does not result from demographic connectivity, as episodic contact during rut, rather than herd switching, is the likely mechanism. Unusually, one small herd (White Mountains) maintained genetic differentiation despite rut overlap with Fortymile. Our data reveal that some herds with different ecological and behavioral attributes are demographically independent but nonetheless genetically connected. Thus, we suggest that managing caribou for an appropriate level of genetic connectivity, while also supporting herd persistence, will be essential to conserve caribou genetic diversity in the region.

Causal role of immune cells in Hashimoto's thyroiditis: Mendelian randomization study.

Hashimoto's thyroiditis (HT) is a common autoimmune disease whose etiology involves a complex interplay between genetics and environment. Previous studies have demonstrated an association between immune cells and HT. However, the casual relationship was not clear. We aimed to explore the causal associations between signatures of immune cells and HT. In this study, bidirectional two-sample Mendelian randomization (MR) analysis was conducted to investigate the potential causal relationship between 731 immune cell signatures and HT by using genome-wide association study (GWAS) data. Heterogeneity and horizontal pleiotropy were detected through extensive sensitivity analyses. The increased levels of six immune phenotypes were observed to be causally associated with increased risk of HT P < 0.01, which were CD3 on CM CD8br, CD3 on CD39+ secreting Treg, HLA DR on CD33dim HLA DR+ CD11b-, CD3 on CD4 Treg, CD62L- plasmacytoid DC %DC, and CD3 on CD45RA+ CD4+. In addition, the levels of FSC-A on HLA DR+ T cell and CD62L on monocyte were associated with disease risk of HT P < 0.01. In addition, HT also had causal effects on CD3 on CM CD8br, CCR2 on monocyte, CD25 on CD39+ resting Treg, and CCR2 on CD62L+ myeloid DC P < 0.05. In this study, we demonstrated the genetic connection between immune cell traits and HT, thereby providing guidance and direction for future treatment and clinical research.

Genetic connectivity of the common octopus (Octopus insularis) along the southwestern Caribbean

AbstractOctopus insularis is a shallow‐water octopus distributed throughout the western Atlantic, the Gulf of Mexico and the Caribbean. To evaluate its phylogeographic pattern, mitochondrial markers (16S rRNA and COIII) and genome‐wide nuclear markers (SNP's) were analyzed in individuals from artisanal fishing in different locations of the Colombian Caribbean coast. Mitochondrial analyzes displayed novel haplotypes (16S = H2, H3 and H4; COIII = H2–H7) and haplotypes shared with distant geographic areas (16S = H1 COIII = H1). The COIII gene did not show genetic differentiation between the analyzed localities, while the 16S gene showed significant differences between Santa Marta and Isla Fuerte. COIII's demographic analysis indicated that the species' effective population size has remained constant. Inferences were made from next‐generation genomic data with restriction site‐associated DNA (ddRAD‐seq) and 6769 polymorphic loci. The pairwise FST test indicated that there are low but significant differences between localities; however, the general molecular analysis of variance (AMOVA) and the principal coordinate analysis showed a lack of spatial structure in the populations analyzed. The Mantel test found no correlation between genetic distance and geographic distance, and the genetic structure analyses showed the presence of one genetic stock. The information obtained in this study indicates the genetic connectivity of O. insularis in the southwestern Caribbean, the absence of putative biogeographic barriers that affect its gene flow, and the crucial role played by life history strategies (planktonic paralarvae) and oceanographic factors to define the current distribution of its genetic diversity in this region.

Chromosomal and genomic analysis suggests single origin and high molecular differentiation of the B chromosome of Abracris flavolineata.

Supernumerary chromosomes (B chromosomes) have been an intriguing subject of study. Our understanding of the molecular differentiation of B chromosomes from an interpopulation perspective remains limited, with most analyses involving chromosome banding and mapping of a few sequences. To gain insights into the molecular composition, origin, and evolution of B chromosomes, we conducted cytogenetic and next-generation sequencing analysis of the repeatome in the grasshopper Abracris flavolineata across various populations. Our results unveiled the presence of B chromosomes in two newly investigated populations and described new satellite DNA sequences. While we observed some degree of genetic connection among A. flavolineata populations, our comparative analysis of genomes with and without B chromosomes provided evidence of two new B chromosome variants. These variants exhibited distinct compositions of various repeat classes, including transposable elements and satellite DNAs. Based on shared repeats, their chromosomal location, and the C-positive heterochromatin content on the B chromosome, these variants likely share a common origin but have undergone distinct molecular differentiation processes, resulting in varying degrees of heterochromatinization. Our data serve as a detailed example of the dynamic and differentiated nature of B chromosome molecular content at the interpopulation level, even when they share a common origin.

Genetic diversity and connectivity of the Irrawaddy dolphin in Southern Thailand: Emphasizing the last fourteen of the Songkhla dolphin status from a microsatellite perspective

Abstract. Budi T, Ninwat S, Sakornwimon W, Thongcham K, Phakphien R, Kalaya C, Phavaphutanon J. 2024. Genetic diversity and connectivity of the Irrawaddy dolphin in Southern Thailand: Emphasizing the last fourteen of the Songkhla dolphin status from a microsatellite perspective. Biodiversitas 25: 1729-1735. Irrawaddy dolphin (Orcaella brevirostris Gray, 1866) can be found in diverse aquatic environments, ranging from coastal to brackish water, stretching from the West of Bengal in India to the central part of the Indonesian archipelago. Despite its widespread distribution and flexible habitat tolerance, Irrawaddy dolphins in Songkhla Lake, Southern Thailand, are hypothesized to be isolated and exhibit concerningly low population numbers, threatening their long-term survival. Limited knowledge exists regarding their population genetics status. This study analyzed 30 samples from Songkhla Lake (SKL) and the Lower Gulf of Thailand (LGT) to assess their genetic diversity, structure, and connectivity using 16 microsatellite loci. Extremely low genetic diversity was observed in SKL (Ho = 0.039±0.039; AR = 1.122±0.489) and LGT (Ho = 0.033±0.033; AR = 1.141±0.566) populations. Population differentiation (FST = 0.033, p&gt;0.05) and clustering analyses based on both Principal Coordinate Analysis (PCoA) and Discriminant Analysis of Principal Component (DAPC) suggest limited genetic divergence and potential panmixia (single genetic pool) between both populations. These findings highlight critical conservation concerns due to low diversity despite the lack of isolation, emphasizing the need for immediate and targeted efforts to ensure the long-term viability of this iconic yet vulnerable population.

POU6F2, a risk factor for glaucoma, myopia and dyslexia, labels specific populations of retinal ganglion cells

Pou6f2 is a genetic connection between central corneal thickness (CCT) in the mouse and a risk factor for developing primary open-angle glaucoma. POU6F2 is also a risk factor for several conditions in humans, including glaucoma, myopia, and dyslexia. Recent findings demonstrate that POU6F2-positive retinal ganglion cells (RGCs) comprise a number of RGC subtypes in the mouse, some of which also co-stain for Cdh6 and Hoxd10. These POU6F2-positive RGCs appear to be novel of ON–OFF directionally selective ganglion cells (ooDSGCs) that do not co-stain with CART or SATB2 (typical ooDSGCs markers). These POU6F2-positive cells are sensitive to damage caused by elevated intraocular pressure. In the DBA/2J mouse glaucoma model, heavily-labeled POU6F2 RGCs decrease by 73% at 8 months of age compared to only 22% loss of total RGCs (labeled with RBPMS). Additionally, Pou6f2−/− mice suffer a significant loss of acuity and spatial contrast sensitivity along with an 11.4% loss of total RGCs. In the rhesus macaque retina, POU6F2 labels the large parasol ganglion cells that form the magnocellular (M) pathway. The association of POU6F2 with the M-pathway may reveal in part its role in human glaucoma, myopia, and dyslexia.

Mediation in bribery as a special type of complicity, reflected in Article 291.1 of the Criminal Code of the Russian Federation

The subject of the study is mediation in bribery as a special type of complicity in Article 291.1 of the Criminal Code of the Russian Federation. The authors consider in detail the aspects of its reflection in the specified article of the Special part of the Criminal Code of the Russian Federation, as a circumstance having a specific similarity with the methods of aiding and abetting, regulated in Part 5 of Article 33 of the General Part of the Criminal Code of the Russian Federation. Special attention is paid to the issue under consideration to clarify the meaning and content of the explanations of the Plenum of the Supreme Court of the Russian Federation, to study the opinions of criminologists in the field of criminal law, the rules of the Russian language and to identify the etymology of the origin of the word. The purpose of the work is to analyze the sign of mediation within the framework of Article 291.1 of the Criminal Code of the Russian Federation for its attribution to a special type of complicity that has a genetic connection with the provisions of Part 5 of Article 33 of the Criminal Code of the Russian Federation. The research is based on the universal dialectical method of cognition. In addition, the article uses such general scientific and private scientific methods as analysis, synthesis, analogy, induction, deduction, historical, systemic-structural, formal-legal. The result of the work was the revealed dissonance in the acts of judicial interpretation related to the criminal law assessment of mediation actions carried out in a small amount, within the framework of Articles 204.1 and 291.1 of the Criminal Code of the Russian Federation and Part 5 of Article 184 of the Criminal Code of the Russian Federation. The authors have revealed that mediation in bribery, in essence, is correlated with complicity (within the meaning of Part 5 of Article 33 of the Criminal Code of the Russian Federation). The novelty of the work lies in the fact that it attempts to study mediation in bribery as a special type of complicity in the context of the systemic connection of the General and Special parts of the Criminal Code of the Russian Federation, with proposals for legislative transformation of parts 5 of Articles 33 and 291.1 of the Criminal Code of the Russian Federation. At the end of the article, a conclusion is drawn about the imperfection of the norms on the types of accomplices to a crime regulated in the General Part of the Criminal Code of the Russian Federation. In particular, the list of complicit actions in Part 5 of Article 33 of the Criminal Code of the Russian Federation is closed, but it is more expedient to make it open, which, it seems, may lead to the exclusion of liability for mediation in bribery (Article 291.1 of the Criminal Code of the Russian Federation).

CORRELATION AND PATH COEFFICIENT ANALYSIS RELATIONSHIPS IN SAFFLOWER (CARTHAMUS TINCTORIUS L.)

An experiment was conducted on 40 genotypes of safflower (Carthamus tinctorius L.) at the Experimental Farm of College of Agriculture, Latur, to examine genetic diversity and connections among characteristics. In Rabi 2020–2021, the experimental design was a complete randomized block design with two replications. The presence of considerable genetic diversity in the experimental materials was confirmed by analysis of variance results for 10 quantitative characters, which showed significant differences for all traits. The phenotypic and genotypic correlation among the traits and their path analysis were calculated. Plant height, number of branches per plant, number of effective capitulum per plant, number of seed per capitulum, and test weight were found to have a strong positive significant relationship with seed yield. This character had a strong and positive relationship toward seed yield. As a result, these characteristics could be considered important for improving safflower seed yield. The character number of branches per plant, plant height, number of effective capsules per plant, number of seed per capitulum, and test weight showed higher direct positive effects and indirect effects through other components traits. Number of seeds per capitulum had the greatest direct positive effect on seed yield per plant, followed by number of branches per plant and number of capsules per plant. As a result, these characteristics must be considered because they are directly relevant to seed yield. Characters like as days to maturity and oil content showed negative direct effects.

Unlocking the secret life of blue mussels: Exploring connectivity in the Skagerrak through biophysical modeling and population genomics.

Knowledge of functional dispersal barriers in the marine environment can be used to inform a wide variety of management actions, such as marine spatial planning, restoration efforts, fisheries regulations, and invasive species management. Locations and causes of dispersal barriers can be studied through various methods, including movement tracking, biophysical modeling, demographic models, and genetics. Combining methods illustrating potential dispersal, such as biophysical modeling, with realized dispersal through, e.g., genetic connectivity estimates, provides particularly useful information for teasing apart potential causes of observed barriers. In this study, we focus on blue mussels (Mytilus edulis) in the Skagerrak-a marginal sea connected to the North Sea in Northern Europe-and combine biophysical models of larval dispersal with genomic data to infer locations and causes of dispersal barriers in the area. Results from both methods agree; patterns of ocean currents are a major structuring factor in the area. We find a complex pattern of source-sink dynamics with several dispersal barriers and show that some areas can be isolated despite an overall high dispersal capability. Finally, we translate our finding into management advice that can be used to sustainably manage this ecologically and economically important species in the future.

Seminatural areas act as reservoirs of genetic diversity for crop pollinators and natural enemies across Europe

AbstractDespite increasing recognition of the importance of the multiple dimensions of biodiversity, including functional or genetic diversity as well as species diversity, most conservation studies on ecosystem service‐providing insects focus on simple diversity measures such as species richness and abundance. In contrast, relatively little is known about the genetic diversity and resilience of pollinators or natural enemies of crop pests to population fragmentation and local extinction. The genetic diversity and demographic dynamics of remnant populations of beneficial insects in agricultural areas can be a useful indicator proving additional insights into their conservation status, but this is rarely evaluated. Although gene flow between agricultural and seminatural areas is key to maintaining genetic diversity, its extent and directionality remain largely unexplored. Here, we apply a pan‐European sampling protocol to quantify genetic diversity and structure and assess gene flow between agricultural and nearby seminatural landscapes in populations of two key ecosystem service‐providing insect species, the lady beetle Coccinella septempunctata, an important predator of aphids and other crop pests, and the bee pollinator Andrena flavipes. We show that A. flavipes populations are genetically structured at the European level, whereas populations of C. septempunctata experience widespread gene flow across the continent and lack any defined genetic structure. In both species, we found that there is high genetic connectivity between populations established in croplands and nearby seminatural areas and, as a consequence, they harbor similar levels of genetic diversity. Interestingly, demographic models for some regions support asymmetric gene flow from seminatural areas to nearby agricultural landscapes. Collectively, our study demonstrates how seminatural areas can serve as genetic reservoirs of both pollinators and natural enemies for nearby agricultural landscapes, acting as sources for recurrent recolonization and, potentially, contributing to enhancing ecosystem service and crop production resilience in the longer term.

Social and genetic connectivity despite ecological variation in a killer whale network.

Philopatric kin-based societies encourage a narrow breadth of conservative behaviours owing to individuals primarily learning from close kin, promoting behavioural homogeneity. However, weaker social ties beyond kin, and across a behaviourally diverse social landscape, could be sufficient to induce variation and a greater ecological niche breadth. We investigated a network of 457 photo-identified killer whales from Norway (548 encounters in 2008-2021) with diet data available (46 mixed-diet individuals feeding on both fish and mammals, and 411 exclusive fish-eaters) to quantify patterns of association within and between diet groups, and to identify underlying correlates. We genotyped a subset of 106 whales to assess patterns of genetic differentiation. Our results suggested kinship as main driver of social bonds within and among cohesive social units, while diet was most likely a consequence reflective of cultural diffusion, rather than a driver. Flexible associations within and between ecologically diverse social units led to a highly connected network, reducing social and genetic differentiation between diet groups. Our study points to a role of social connectivity, in combination with individual behavioural variation, in influencing population ecology in killer whales.

Microscale hydrogen, carbon, and nitrogen isotopic diversity of organic matter in asteroid Ryugu

We report the H, C, and N isotopic compositions of microscale (0.2 to 2 µm) organic matter in samples of asteroid Ryugu and the Orgueil CI carbonaceous chondrite. Three regolith particles of asteroid Ryugu, returned by the Hayabusa2 spacecraft, and several fragments of Orgueil were analyzed by NanoSIMS isotopic imaging. The isotopic distributions of the Ryugu samples from two different collection spots are closely similar to each other and to the Orgueil samples, strengthening the proposed Ryugu-CI chondrite connection. Most individual sub-μm organic grains have isotopic compositions within error of bulk values, but 2–10 % of them are outliers exhibiting large isotopic enrichments or depletions in D, 15N, and/or 13C. The H, C and N isotopic compositions of the outliers are not correlated with each other: while some organic grains are both D- and 15N-enriched, many are enriched or depleted in one or the other system. This most likely points to a diversity in isotopic fractionation pathways and thus diversity in the local formation environments for the individual outlier grains. The observation of a relatively small population of isotopic outlier grains can be explained either by escape from nebular and/or parent body homogenization of carbonaceous precursor material or addition of later isotopic outlier grains. The strong chemical similarity of isotopically typical and isotopically outlying grains, as reflected by synchrotron x-ray absorption spectra, suggests a genetic connection and thus favors the former, homogenization scenario. However, the fact that even the least altered meteorites show the same pattern of a small population of outliers on top of a larger population of homogenized grains indicates that some or most of the homogenization occurred prior to accretion of the macromolecular organic grains into asteroidal parent bodies.

Genetic history of esophageal cancer group in southwestern China revealed by Y‐chromosome STRs and genomic evolutionary connection analysis

Genetic and environmental factors play crucial roles in the development of esophageal cancer (EC) and contribute uniquely or cooperatively to human cancer susceptibility. Sichuan is located in the interior of southwestern China, and the northern part of Sichuan is one of the regions with a high occurrence of EC. However, the factors influencing the high incidence rate of EC in the Sichuan Han Chinese population and its corresponding genetic background and origins are still poorly understood. Here, we utilized genome-wide single nucleotide polymorphisms (SNPs) and Y-chromosome short tandem repeats (Y-STRs) to characterize the genetic structure, connection, and origin of cancer groups and general populations. We generated Y-STR-based haplotype data from 214 Sichuan individuals, including the Han Chinese EC population and a control group of Han Chinese individuals. Our results, obtained from Y-STR-based population statistical methods (analysis of molecular variance (AMOVA), principal component analysis (PCA), and phylogenetic analysis), demonstrated that there was a genetic substructure difference between the EC population in the high-incidence area of northern Sichuan Province and the control population. Additionally, there was a strong genetic relationship between the EC population in the northern Sichuan high-incidence area and those at high risk in both the Fujian and Chaoshan areas. In addition, we obtained high-density SNP data from saliva samples of 60 healthy Han Chinese individuals from three high-prevalence areas of EC in China: Sichuan Nanchong, Fujian Quanzhou, and Henan Xinxiang. As inferred from the allele frequency of SNPs and sharing patterns of haplotype segments, the evolutionary history and admixture events suggested that the Han population from Nanchong in northern Sichuan Province shared a close genetic relationship with the Han populations from Xinxiang in Henan Province and Quanzhou in Fujian Province, both of which are regions with a high prevalence of EC. Our study illuminated the genetic profile and connection of the Northern Sichuan Han population and enriched the genomic resources and features of the Han Chinese populations in China, especially for the Y-STR genetic data of the Han Chinese EC population. Populations living in different regions with high incidences of EC may share similar genetic backgrounds, which offers new insights for further exploring the genetic mechanisms underlying EC.

Sequence Analysis of some species in the genus Amaranthus L. using Ribulose-1.5 - bisphosphate carboxylase/oxygenase (rbcL) genes

Bioinformatics is a novel method to investigate evolutionary relationships and genetic diversity among species. This study assessed the evolutionary patterns and genetic diversity of Amaranthus species using ribulose-1.5-bisphosphate carboxylase/oxygenase (rbcL gene). A total of 20 full FASTA-format rbcL gene sequences for accessions of Amaranthus tricolor, A. dubius, A. cruentus, A. viridis, and A. spinosus from different regions were retrieved from the National Center for Biotechnology Information. Multiple sequence alignment was used to determine genetic variations. A phylogenetic tree was constructed using neighbor-joining clustering method while a distant matrix was created using Tamura-Nei genetic distance model. From position 1 to 22 in nucleotide alignment, only accession KX082771.1 from USA, aligns. The exclusive alignment in this region suggests an exceptionally conserved sequence among species, implying a common genetic origin. However, from position 23 to 50, nine different accessions namely MN192576.1, MN204800.1, EF590496.1, GQ248546.1, OQ737000.1, MG246937.1, MN104855.1, MN104858.1, and MN04859.1 align. The phylogenetic tree representing the evolutionary relationships offers insights into the genetic diversity and relatedness of these species within specific regions. The genetic distance matrix shows that sequences within the same region share relatively high similarity scores, indicating a genetic connection likely influenced by their geographic proximity. However, sequences from different regions, exhibit moderate genetic differences, emphasizing the genetic diversity across geographically distinct regions. The observed genetic diversity and evolutionary relationships among accessions of Amaranthus revealed by rbcL genes highlight the unique genetic features of these species in different regions, and therefore should be explored for their genetic improvement and conservation purposes.

Barriers and corridors: Assessment of gene flow and movement among red panda populations in eastern Himalayas

Landscape features can impede dispersal, gene flow, and population demography, resulting in the formation of several meta-populations within a continuous landscape. Understanding a species' ability to overcome these barriers is critical for predicting genetic connectivity and population persistence, and implementing effective conservation strategies. In the present study, we conducted a fine-scale spatial genetic analysis to understand the contemporary gene flow within red panda populations in the Eastern Himalayas. Employing geometric aspects of reserve design, we delineated the critical core habitats for red pandas, which comprise 14.5 % of the landscape (12,189.75 Km2), with only a mere 443 Km2 falling within the protected areas. We identified corridors among the core habitats, which may be vital for the species' long-term genetic viability. Furthermore, we identified substantial landscape barriers, including Sela Pass in the western region, Siang river in the central region, and the Dibang river, Lohit river, along with Dihang, Dipher, and Kumjawng passes in the eastern region, which hinder gene flow. We suggest managing red panda populations through the creation of Community Conservation Reserves in the identified core habitats, following landscape-level management planning based on the core principles of geometric reserve design. This includes a specific emphasis on identified core habitats of red panda (CH-RP 5 and CH-RP 8) to facilitate corridors and implement meta-population dynamics. We propose the development of a comprehensive, long-term conservation and management plan for red pandas in the transboundary landscape, covering China, Nepal, and Bhutan.