scholarly journals A Comprehensive Curation Shows the Dynamic Evolutionary Patterns of Prokaryotic CRISPRs

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Guoqin Mai ◽  
Ruiquan Ge ◽  
Guoquan Sun ◽  
Qinghan Meng ◽  
Fengfeng Zhou
Keyword(s):  
Related Species ◽  
Evolutionary History ◽  
Genetic Element ◽  
Evolutionary Patterns ◽  
Closely Related Species ◽  
Prokaryotic Genomes ◽  
Active Regulation ◽  
Short Palindromic Repeat ◽  
Comprehensive Comparison ◽  
Cas Gene

Motivation.Clustered regularly interspaced short palindromic repeat (CRISPR) is a genetic element with active regulation roles for foreign invasive genes in the prokaryotic genomes and has been engineered to work with the CRISPR-associated sequence (Cas) gene Cas9 as one of the modern genome editing technologies. Due to inconsistent definitions, the existing CRISPR detection programs seem to have missed some weak CRISPR signals.Results.This study manually curates all the currently annotated CRISPR elements in the prokaryotic genomes and proposes 95 updates to the annotations. A new definition is proposed to cover all the CRISPRs. The comprehensive comparison of CRISPR numbers on the taxonomic levels of both domains and genus shows high variations for closely related species even in the same genus. The detailed investigation of how CRISPRs are evolutionarily manipulated in the 8 completely sequenced species in the genusThermoanaerobacterdemonstrates that transposons act as a frequent tool for splitting long CRISPRs into shorter ones along a long evolutionary history.

scholarly journals The rapid evolution of alternative splicing in plants

2017 ◽  
Author(s):  
Zhihao Ling ◽  
Thomas Brockmöller ◽  
Ian T. Baldwin ◽  
Shuqing Xu
Keyword(s):  
Alternative Splicing ◽  
Related Species ◽  
Donor Site ◽  
Rapid Evolution ◽  
Acceptor Site ◽  
Mrna Levels ◽  
Evolutionary Patterns ◽  
Closely Related Species ◽  
Nonsense Mediated Decay ◽  
Splicing Regulators

AbstractAlternative pre-mRNA splicing (AS) is prevalent among all plants and is involved in many interactions with environmental stresses. However, the evolutionary patterns and underlying mechanisms of AS in plants remain unclear. By analyzing the transcriptomes of six plant species, we revealed that AS diverged rapidly among closely related species, largely due to the gains and losses of AS events among orthologous genes. Furthermore, AS that generates transcripts containing premature termination codons (PTC), although only representing a small fraction of the total AS, are more conserved than those that generate non-PTC containing transcripts, suggesting that AS coupled with nonsense-mediated decay (NMD) might play an important role in regulating mRNA levels post-transcriptionally. With a machine learning approach we analyzed the key determinants of AS to understand the mechanisms underlying its rapid divergence. Among the studied species, the presence/absence of alternative splicing site (SS) within the junction, the distance between the authentic SS and the nearest alternative SS, the size of exon-exon junctions were the major determinants for both alternative 5’ donor site and 3’acceptor site, suggesting a relatively conserved AS mechanism. Comparative analysis further demonstrated that variations of the identified AS determinants, mostly are located in introns, significantly contributed to the AS turnover among closely related species in both Solanaceae and Brassicaceae taxa. These new mechanistic insights into the evolution of AS in plants highlight the importance of post-transcriptional regulation in mediating plant-environment interactions.One sentence summaryChanges of intron located splicing regulators contributed to the rapid evolution of alternative splicing in plants.

scholarly journals Evolutionary Patterns in the Genus Homo

2021 ◽  
Vol 21 (01) ◽  
Author(s):  
Nisar A. Shar
Keyword(s):  
Related Species ◽  
Homo Sapiens ◽  
Demographic History ◽  
Human Intelligence ◽  
Evolutionary Patterns ◽  
Closely Related Species ◽  
Genus Homo ◽  
Wide Range ◽  
History Of

ABSTRACT The demographic history of Homo sapiens is complex; it involves a wide range of migrations and genetic adaptations. One of the closely related species to Homo sapiens is Neanderthals, which became extinct about 30,000 years ago. The aim of this research is to compare Homo sapiens with Neanderthals and chimpanzees to understand the patterns of inheritance and survival instincts of Homo sapiens. Results show that out of all selected groups of genes in this study, metabolism, and language genes are found to be the most evolving group of genes. This shows that these most evolving genes are contributing to the advancement of Homo sapiens. However, after comparing human intelligence genes with the primates, it is found that exonic regions are contributing more to the evolution of human intelligence hence, making Homo sapiens unique in terms of intelligence.

scholarly journals Eversion and withdrawal of an intromittent organ before sexual maturation prepares male beetles for copulation

2017 ◽  
Vol 4 (8) ◽  
pp. 161029 ◽  
Author(s):  
Yoko Matsumura ◽  
Takuya Kubo
Keyword(s):  
Phylogenetic Tree ◽  
Sexual Maturation ◽  
Related Species ◽  
Evolutionary History ◽  
Active State ◽  
Surface Structures ◽  
Closely Related Species ◽  
Spermathecal Duct ◽  
History Of ◽  
Coiled State

Some species of criocerine beetles have a hyper-elongated part of the intromittent organ called a flagellum. In resting position, the flagellum is stored in a specialized internal sac in the intromittent organ. This specialized state of the flagellum and internal sac is indispensable during copulation for flagellar insertion into the female spermathecal duct for sperm transfer. However, the morphogenesis of the flagellum does not generate the active state of the flagellum; rather, the flagellum is generated in an inactive and completely coiled state. After eclosion, males of Lema coronata evert and withdraw the internal sac multiple times before sexual maturation, without mounting a female. This behaviour serves to uncoil the flagellum and guide it into the active state with the aid of surface structures on the internal sac. A closely related species, Lema dilecta , also has a long flagellum and undergoes the same behaviour to place the flagellum in the active position. However, some other species of criocerine beetles with much shorter flagella can attain the active state without exhibiting this behaviour. Based on a previously proposed phylogenetic tree, we discuss the evolutionary history of the hyper-elongation of the flagellum and associated behaviour.

THE EVOLUTIONARY HISTORY OF DROSOPHILA BUZZATII. III. CYTOGENETIC RELATIONSHIPS BETWEEN TWO SIBLING SPECIES OF THE BUZZATII CLUSTER

Genetics ◽  
1982 ◽  
Vol 101 (3-4) ◽  
pp. 503-518 ◽  
Author(s):  
A Ruiz ◽  
A Fontdevila ◽  
M Wasserman
Keyword(s):  
Salivary Gland ◽  
Sibling Species ◽  
Related Species ◽  
Evolutionary History ◽  
South American ◽  
Closely Related Species ◽  
Drosophila Buzzatii ◽  
Repleta Group ◽  
Chromosomal Data ◽  
History Of

ABSTRACT Drosophila buzzatii has been found sympatric in Argentina with a closely-related sibling species, D. serido. The biogeographical, reproductive and chromosomal data allow us to combine these species into an evolutionary unit, the buzzatii cluster. Salivary gland chromosomes also have been used to determine their phylogenetic relationships with other closely related species, showing that the buzzatii cluster species share two inversions—2d  2 and 2s  6—with the species of the martensis cluster. Both clusters arose from South American populations of the ancestor of the mulleri complex, and we propose to include D. buzzatii and D. serido in the mulleri complex of the repleta group.

scholarly journals Evolutionary history of the Drosophila bipectinata species complex

2005 ◽  
Vol 85 (1) ◽  
pp. 23-46 ◽  
Author(s):  
ARTYOM KOPP ◽  
OLGA BARMINA
Keyword(s):  
Related Species ◽  
Genetic Divergence ◽  
Species Complex ◽  
Evolutionary History ◽  
Genetic Basis ◽  
Functional Differentiation ◽  
Sympatric Species ◽  
Closely Related Species ◽  
Drosophila Bipectinata ◽  
History Of

Groups of recently diverged species offer invaluable glimpses into the history and genetic basis of speciation and phenotypic evolution. In this report, we combine phylogenetic and population-genetic approaches to reconstruct the evolutionary history of the Drosophila bipectinata species complex. This complex is a group of four closely related, largely sympatric species – D. bipectinata, D. parabipectinata, D. malerkotliana and D. pseudoananassae. Using the sequences of one mitochondrial and six nuclear loci, we show that D. bipectinata and D. parabipectinata are the two most closely related species, and that together with D. malerkotliana they form a monophyletic clade to which D. pseudoananassae is a relatively distant outgroup. Genetic divergence among D. bipectinata, D. parabipectinata and D. malerkotliana is extremely low, and we estimate that these species diverged only 283000–385000 years ago. We also find that mitochondrial DNA shows evidence of recent gene flow across species boundaries. Despite the low genetic divergence, species of the bipectinata complex show an unusually high degree of morphological differentiation. This contrast underscores the importance of understanding the genetic basis of functional differentiation among closely related species.

scholarly journals Allometry and Interspecific Differences in the Facial Cranium of Two Closely Related Macaque Species

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Tsuyoshi Ito ◽  
Takeshi Nishimura ◽  
Masanaru Takai
Keyword(s):  
Body Size ◽  
Related Species ◽  
Evolutionary History ◽  
Macaca Fascicularis ◽  
Size Variation ◽  
Critical Feature ◽  
Closely Related Species ◽  
Macaque Monkeys ◽  
Interspecific Differences ◽  
History Of

Interpreting evolutionary history of macaque monkeys from fossil evidence is difficult, because their evolutionary fluctuations in body size might have removed or formed important morphological features differently in each lineage. We employed geometric morphometrics to explore allometric trajectories of craniofacial shape in two closely related species, Macaca fascicularis and M. fuscata. These two species exhibit a single shared allometric trajectory in superoinferior deflection of the anterior face, indicating that the differences in this feature can be explained by size variation. In contrast, two parallel trajectories are demonstrated in craniofacial protrusion, indicating that even if they are comparable in size, M. fuscata has a higher and shorter face than M. fascicularis. The degree of facial protrusion is most likely a critical feature for phyletic evaluation in the fascicularis group. Such analyses in various macaques would help to resolve controversies regarding phyletic interpretations of fossil macaques.

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