scholarly journals Plateau Grass and Greenhouse Flower? Distinct Genetic Basis of Closely Related Toad Tadpoles Respectively Adapted to High Altitude and Karst Caves

Genes ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 123
Author(s):  
Liming Chang ◽  
Wei Zhu ◽  
Shengchao Shi ◽  
Meihua Zhang ◽  
Jianping Jiang ◽  
...  

Genetic adaptation to extremes is a fascinating topic. Nevertheless, few studies have explored the genetic adaptation of closely related species respectively inhabiting distinct extremes. With deep transcriptome sequencing, we attempt to detect the genetic architectures of tadpoles of five closely related toad species adapted to the Tibetan Plateau, middle-altitude mountains and karst caves. Molecular evolution analyses indicated that not only the number of fast evolving genes (FEGs), but also the functioning coverage of FEGs, increased with elevation. Enrichment analyses correspondingly revealed that the highland species had most of the FEGs involved in high-elevation adaptation, for example, amino acid substitutions of XRCC6 in its binding domains might improve the capacity of DNA repair of the toad. Yet, few FEGs and positively selected genes (PSGs) involved in high-elevation adaptation were identified in the cave species, and none of which potentially contributed to cave adaptation. Accordingly, it is speculated that in the closely related toad tadpoles, genetic selection pressures increased with elevation, and cave adaptation was most likely derived from other factors (e.g., gene loss, pseudogenization or deletion), which could not be detected by our analyses. The findings supply a foundation for understanding the genetic adaptations of amphibians inhabiting extremes.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maoliang Zhang ◽  
Zhengfu Guo ◽  
Sheng Xu ◽  
Peter H. Barry ◽  
Yuji Sano ◽  
...  

AbstractThe episodic growth of high-elevation orogenic plateaux is controlled by a series of geodynamic processes. However, determining the underlying mechanisms that drive plateau growth dynamics over geological history and constraining the depths at which growth originates, remains challenging. Here we present He-CO2-N2 systematics of hydrothermal fluids that reveal the existence of a lithospheric-scale fault system in the southeastern Tibetan Plateau, whereby multi-stage plateau growth occurred in the geological past and continues to the present. He isotopes provide unambiguous evidence for the involvement of mantle-scale dynamics in lateral expansion and localized surface uplift of the Tibetan Plateau. The excellent correlation between 3He/4He values and strain rates, along the strike of Indian indentation into Asia, suggests non-uniform distribution of stresses between the plateau boundary and interior, which modulate southeastward growth of the Tibetan Plateau within the context of India-Asia convergence. Our results demonstrate that deeply-sourced volatile geochemistry can be used to constrain deep dynamic processes involved in orogenic plateau growth.


2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Jacqueline Eng ◽  
Mark Aldenderfer

Anthropological research in the high-elevation regions of northwestern Nepal offers insights into the populationhistory of the Himalayan arc through a multi- and interdisciplinary approach that includes not only archaeologicaldata and historic and ethnographic accounts but also genomic, isotopic, and bioarchaeologicaldata, as well as innovative use of thermal niche modeling for paleoclimate reconstruction. Together these linesof evidence have allowed us to address project questions about human settlement into the region, including(1) sources of population movements into high-elevation environments of the Himalayan arc and (2) bioculturaladaptations to high-mountain environments. In this paper we compare research at several communalmortuary sites, each with a rich assemblage of material culture and human burials: Mebrak (400 B.C.–A.D. 50),Kyang (400–175 B.C.), and Samdzong (A.D. 450–650), as well as intriguing insights from finds in the earlier (ca.1250–450 B.C.) sites of Lubrak, Chokhopani, and Rhirhi. Our genomic findings demonstrate population originsfrom the Tibetan plateau, despite South Asian material culture recovered in early sites. Bioarchaeological findingsof low frequencies of non-specific stress and trauma indicate successful biocultural adaptation to highaltitudeconditions of hypoxia, cold, and low resource availability, potentially through buffering from exchangenetworks and local cultural practices, alongside high-altitude selected alleles. An integrative, multidisciplinaryapproach thus offers significantly greater opportunities for developing a more nuanced understanding of thepast processes of migration, settlement, and biocultural adaptation in the region. La investigación antropológica de las alturas del noroeste de Nepal nos proporciona conocimientos de la historiade la población del arco Himalaya a través de un enfoque multidisciplinario e interdisciplinario que incluyeno solamente datos arqueológicos y relatos históricos y etnográficos, sino también datos genómicos, isotópicos,y bioarqueológicos, tanto como uso innovador del modelado del nicho térmico para la reconstrucción paleoclimática.En conjunto, estas líneas de evidencia nos han permitido abordar temas sobre el asentamiento humanade la región, como: (1) los orígenes del movimiento hacia ambientes en las alturas del arco del Himalaya;y (2) las adaptaciones bioculturales necesarias para vivir en las alturas. En este artículo comparamos las investigacionesde varios mortuorios comunales que ofrecen conjuntos abundantes de entierros humanos y artefactosrelacionados: Mebrak (400 a.C.–d.C. 50), Kyang (400–175 a.C.), and Samdzong (d.C. 450–650), así como loshallazgos intrigantes de sitios anteriores (ca. 1250–450 a.C.) de Lubrak, Chokhopani, y Rhirhi. Nuestros datosgenómicos sugieren orígenes de le población del altiplano tibetano, a pesar del material que deriva del sur de Asia que se ha recuperado de los sitios mas tempranos. Los hallazgos bioarqueológicos demuestran niveles bajosde estrés y trauma inespecífico, y sugieren éxito en adaptación biocultural, a pesar de las condiciones de hipoxia,frio, y los recursos escasos en este ambiente. Es posible que alelos seleccionados a las alturas, junto con sistemasde intercambio y las costumbres locales contribuyeron al éxito de la adaptación. Por lo tanto, un enfoque multidisciplinarioque integra todas las evidencias ofrece una comprensión mas detallada de los procesos de migración,asentamiento, y adaptación biocultural de la región.


Author(s):  
Mike Searle

The Tibetan Plateau is by far the largest region of high elevation, averaging just above 5,000 metres above sea level, and the thickest crust, between 70 and 90 kilometres thick, anywhere in the world. This huge plateau region is very flat—lying in the internally drained parts of the Chang Tang in north and central Tibet, but in parts of the externally drained eastern Tibet, three or four mountain ranges larger and higher than the Alps rise above the frozen plateau. Some of the world’s largest and longest mountain ranges border the plateau, the ‘flaming mountains’ of the Tien Shan along the north-west, the Kun Lun along the north, the Longmen Shan in the east, and of course the mighty Himalaya forming the southern border of the plateau. The great trans-Himalayan mountain ranges of the Pamir and Karakoram are geologically part of the Asian plate and western Tibet but, as we have noted before, unlike Tibet, these ranges have incredibly high relief with 7- and 8-kilometre-high mountains and deeply eroded rivers and glacial valleys. The western part of the Tibetan Plateau is the highest, driest, and wildest area of Tibet. Here there is almost no rainfall and rivers that carry run-off from the bordering mountain ranges simply evaporate into saltpans or disappear underground. Rivers draining the Kun Lun flow north into the Takla Makan Desert, forming seasonal marshlands in the wet season and a dusty desert when the rivers run dry. The discovery of fossil tropical leaves, palm tree trunks, and even bones from miniature Miocene horses suggest that the climate may have been wetter in the past, but this is also dependent on the rise of the plateau. Exactly when Tibet rose to its present elevation is a matter of great debate. Nowadays the Indian Ocean monsoon winds sweep moisture-laden air over the Indian sub-continent during the summer months (late June–September). All the moisture is dumped as the summer monsoon, the torrential rains that sweep across India from south-east to north-west.


2010 ◽  
Vol 14 (3) ◽  
pp. 481-489 ◽  
Author(s):  
J. Liu ◽  
S. Kang ◽  
T. Gong ◽  
A. Lu

Abstract. This study analyzed satellite images and long term climate variables from a high-elevation meteorological station (4730 m) and streamflow records to examine hydrological response of Nam Co Lake (4718 m), the largest lake on the Tibetan Plateau, over the last 50 years. The results show the lake area extended by 51.8 km2 (2.7% of the total area) when compared with the area in 1976. This change is associated with an annual precipitation increase of 65 mm (18.6%), annual and winter mean temperature increases of 0.9 °C and 2.1 °C respectively, an annual runoff increase of 20% and an annual pan evaporation decrease of about 2%, during the past 20 years. The year of the change point in annual precipitation, air temperature, annual pan evaporation and runoff occurred in 1971, 1983, 1997 and 1997, respectively. The timing of the lake growth corresponds with the abrupt increase in annual precipitation and runoff since the mid-1990s.


2004 ◽  
Vol 83 (2) ◽  
pp. 83-89 ◽  
Author(s):  
MUNEO MATSUDA ◽  
YOSHIKO N. TOBARI

Parthenogenetic strains of several species have been found in the genus Drosophila. The mode of diploidization in the eggs of females has been found to be post-meiotic nuclear fusion. The genetic basis for this parthenogenesis is not understood but is believed to be under the control of a complex polygenic system. We found parthenogenetic females in an isofemale strain (LAE345) of D. pallidosa-like collected in 1981 at Lae, Papua New Guinea, and established a parthenogenetically reproducing strain. Parthenogenetic strains of D. ananassae and D. pallidosa collected at Taputimu, American Samoa had also been established by Futch (1972). D. ananassae, D. pallidosa and D. pallidosa-like are very closely related species belonging to the ananassae complex of the ananassae species subgroup of the melanogaster species group. Using these three species, we found that more than 80% of females from parthenogenetic strains produced progeny parthenogenetically and that inter-specific hybrid females also produced impaternate progeny. In the present report, we demonstrate that the mode of parthenogenesis of D. ananassae appears to be the post-meiotic nuclear doubling of a single meiotic product, and that a major gene responsible for the parthenogenesis maps to the left arm of the second chromosome of D. ananassae. We also suggest that the genetic basis for parthenogenesis capacity may be identical among the three closely related species. We discuss the function of the gene required for parthenogenesis and its significance for the evolutionary process.


Lupus ◽  
2016 ◽  
Vol 26 (3) ◽  
pp. 307-310 ◽  
Author(s):  
J H Yusuf ◽  
D Kaliyaperumal ◽  
M Jayaraman ◽  
G Ramanathan ◽  
P Devaraju

Objectives Lupus is a classical systemic autoimmune disease with genetics as one of the well known causative factors for the disease pathogenesis. Toll-like receptors are the major pattern recognition receptors associated with innate immunity and also act as an interface with the adaptive immunity. Genetic polymorphisms in genes encoding TLRs were implicated in the development of infections, malignancies and autoimmune diseases. TLR9 is a member of TLR family, and recognizes the CpG DNA motifs of pathogens. Though the incidence rate of lupus in Asians was reported to be low (30 − 50/100,000 population), poor disease prognosis due to higher incidence of renal complications and aggressive disease worsens the scenario. The ability of TLR9 to detect and elicit an immune response against double-stranded DNA makes TLR9 a relevant factor to be tested for its association with the clinical and serological phenotypes of lupus. However, lack of relevant genetic data on normative frequencies of the TLR9 (rs187084) polymorphism may serve as a constraint to derive the sample size to conduct case control association studies. Hence this study was conducted to establish the normative frequency of TLR9 (rs187084) polymorphism in Indian Tamils. Materials and methods The TLR9 (rs187084) polymorphism was screened in South Indian Tamils ( n = 208) by PCR-RFLP. Results and discussion We observed a higher occurrence of the mutant allele (65%) in South Indian Tamils. No gender disparity with respect to the mutant allele frequency was observed. The higher incidence of mutant allele in both genders suggests that this population had undergone a genetic selection pressure as an evolutionary genetic measure to withstand the prevailing endemic infections like TB and malaria. Though the enhanced expression of TLR9 was protective against infections, it may also influence the development of autoimmune diseases. Conclusion The higher incidence of theTLR9 (rs187084) over-expression mutation in Indian Tamils is suggestive of a genetic adaptation or selection pressure to withstand the prevailing endemic infectious and parasitic diseases. However, this genetic adaptation poses a greater risk to develop autoimmune diseases like SLE etc through complex gene environment interactions. The normative frequency of the TLR9 (rs187084) polymorphism established in our population could now be used to define the sample size for future case control studies.


2021 ◽  
Author(s):  
Sagar Sharad Shinde ◽  
Sandhya Sharma ◽  
Lokdeep Teekas ◽  
Ashutosh Sharma ◽  
Nagarjun Vijay

Skeletal muscle fibers rely upon either oxidative phosphorylation or glycolytic pathway to achieve muscular contractions that power mechanical movements. Species with energy-intensive adaptive traits that require sudden bursts of energy have a greater dependency on fibers that use the glycolytic pathway. Glycolytic fibers have decreased reliance on OXPHOS and lower mitochondrial content compared to oxidative fibers. Hence, we hypothesized that adaptive gene loss might have occurred within the OXPHOS pathway in lineages that largely depend on glycolytic fibers. The protein encoded by the COA1/MITRAC15 gene with conserved orthologs found in budding yeast to humans promotes mitochondrial translation. We show that gene disrupting mutations have accumulated within the COA1/MITRAC15 gene in the cheetah, several species of galliforms, and rodents. The genomic region containing COA1/MITRAC15 is a well-established evolutionary breakpoint region in mammals. Careful inspection of genome assemblies of closely related species of rodents and marsupials suggests two independent COA1/MITRAC15 gene loss events co-occurring with chromosomal rearrangements. Besides recurrent gene loss events, we document changes in COA1/MITRAC15 exon structure in primates and felids. The detailed evolutionary history presented in this study reveals the intricate link between skeletal muscle fiber composition and dispensability of the chaperone-like role of the COA1/MITRAC15 gene.


Phytotaxa ◽  
2021 ◽  
Vol 479 (1) ◽  
pp. 1-22
Author(s):  
KIM J. KRAHN ◽  
ANJA SCHWARZ ◽  
CARLOS E. WETZEL ◽  
SERGIO COHUO-DURÁN ◽  
GERHARD DAUT ◽  
...  

Three new needle-shaped Fragilaria species from freshwater lake Apastepeque in El Salvador (Fragilaria salvadoriana sp. nov., F. maarensis sp. nov.) and subsaline lake Nam Co on the Tibetan Plateau (F. huebeneri sp. nov.) are described and compared based on light and scanning electron microscopy observations and morphometric analyses. Fragilaria salvadoriana sp. nov. is characterized by narrowly linear-lanceolate, sometimes centrally constricted valves, subcapitate to rarely capitate apices, and a distinct, dented appearing central area. Striae are composed of 2−5 occluded areolae. It can be differentiated from similar needle-shaped species by the valve outline, relatively low striae density, and shark fin-shaped spines. Characteristic of F. maarensis sp. nov. are a very narrowly lanceolate valve outline and subcapitate apices. The apical pore field is composed of 2–3 rows of poroids and acute, irregularly oriented spines are present at the junction between valve face and mantle. This taxon is clearly different from other Fragilaria species, displaying a high length-to-width ratio and a low number of areolae per stria. The Tibetan species, F. huebeneri sp. nov., forms long ribbon-like colonies linked together by spatula-shaped spines. Valves have subcapitate apices, a spindle- to needle-shaped outline and an indistinct central area. Striae are alternate and composed of 3–5 areolae per stria. Teratological forms of F. huebeneri sp. nov. were commonly observed in the sediment trap samples. Fragilaria salvadoriana sp. nov. and F. maarensis sp. nov. were found in a warm, tropical crater lake characterized by low conductivity and dissolved oxygen content, medium alkaline pH, and magnesium-calcium-bicarbonate-rich waters. Fragilaria huebeneri sp. nov. was frequent in a large, high elevation lake with increased specific conductivity, alkaline pH and sodium-bicarbonate-rich waters. The new species are compared to morphologically similar species from the genus Fragilaria Lyngbye and ecological preferences are discussed.


2019 ◽  
Author(s):  
K. Kreger ◽  
B. Shaban ◽  
E. Wapstra ◽  
C.P. Burridge

AbstractPhylogeography provides a means to understand mechanisms that shaped the distribution and abundance of species, including the role of past climate change. While concordant phylogeographic relationships across diverse taxa suggest shared underlying mechanisms (“phylogeographic parallelism”), it is also possible that similar patterns are the product of different mechanisms (“phylogeographic convergence”), reflecting variation among taxa in factors such as environmental tolerances, life histories, and vagility. Hence, phylogeographic concordance among closely related and ecologically similar species can yield a more confident understanding of the past mechanisms which shaped their distribution and abundance. This study documented mitochondrial and nuclear phylogeographic patterns in the ectotherm skink, Niveoscincus metallicus, which occupies historically glaciated regions of Tasmania, and contrasted these with the closely related and broadly sympatric N. ocellatus. Major phylogeographic breaks were similar in location between the two species, and indicative of isolation caused by retreat from high elevation areas during glaciations, but with long-term persistence at multiple low elevation sites. Hence, Pleistocene glacial refugia were altitudinal rather than latitudinal, a pattern mirrored in other temperate Southern Hemisphere taxa. This study also examined phylogeographic patterns across the intermittently inundated Bassian Isthmus between mainland Australia and the island of Tasmania, and revealed that structuring is similarly maintained when populations were physically isolated during interglacial rather than glacial stages.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sagar Sharad Shinde ◽  
Sandhya Sharma ◽  
Lokdeep Teekas ◽  
Ashutosh Sharma ◽  
Nagarjun Vijay

AbstractSkeletal muscle fibers rely upon either oxidative phosphorylation or the glycolytic pathway with much less reliance on oxidative phosphorylation to achieve muscular contractions that power mechanical movements. Species with energy-intensive adaptive traits that require sudden bursts of energy have a greater dependency on glycolytic fibers. Glycolytic fibers have decreased reliance on OXPHOS and lower mitochondrial content compared to oxidative fibers. Hence, we hypothesized that gene loss might have occurred within the OXPHOS pathway in lineages that largely depend on glycolytic fibers. The protein encoded by the COA1/MITRAC15 gene with conserved orthologs found in budding yeast to humans promotes mitochondrial translation. We show that gene disrupting mutations have accumulated within the COA1 gene in the cheetah, several species of galliform birds, and rodents. The genomic region containing COA1 is a well-established evolutionary breakpoint region in mammals. Careful inspection of genome assemblies of closely related species of rodents and marsupials suggests two independent COA1 gene loss events co-occurring with chromosomal rearrangements. Besides recurrent gene loss events, we document changes in COA1 exon structure in primates and felids. The detailed evolutionary history presented in this study reveals the intricate link between skeletal muscle fiber composition and the occasional dispensability of the chaperone-like role of the COA1 gene.


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