Gastric Brooding - a New Form in a Recently Discovered Australian Frog of the Genus Rheobatrachus

1986 ◽  
Vol 34 (2) ◽  
pp. 205 ◽  
Author(s):  
ASY Leong ◽  
MJ Tyler ◽  
DJC Shearman

The phenomenon of gastric brooding and oral birth displayed by the Australian frog Rheobatrachus silus has not previously been observed in the Animal Kingdom. This report describes another example of gastric brooding in a recently discovered, closely related species, Rheobatrachus vitellinus. The stomach of a female R. vitellinus that had given birth to 22 froglets revealed morphologic changes which were quite different to those described in R. silus. Unlike the atrophy of the mucosa and acid-secreting oxyntic cells in the latter species, there was no evidence of major structural changes in the brooding stomach of R. vitellinus. Furthermore, no differences were observed in the light microscopic appearances of the stomach in the brooding female and that from a non-brooding female and male R. vitellinus. A striking finding not observed in the non-brooding stomachs of R. vitellinus nor in R. silus was the presence of widespread and numerous apoptotic bodies in the gastric epithelium. The apoptotic bodies were recognized as phagocytosed fragments of eosinophilic cytoplasm and pyknotic nuclear material. Ultrastructurally, well preserved organelles were observed in the phagocytosed fragments. This diffuse deletion of cells and the striking absence of major structural changes in the brooding stomach may indicate a dichotomy in the evolution of this bizarre and unique reproductive habit.

Genetika ◽  
2015 ◽  
Vol 47 (2) ◽  
pp. 451-468 ◽  
Author(s):  
Malahat Taban ◽  
Masoud Sheidai ◽  
Zahra Noormohammadi ◽  
Narjes Azizi ◽  
Somayeh Ghasemzadeh-Baraki ◽  
...  

Helichrysum armenium and H. rubicundum are two medicinally important plants of Iran that are distributed in various regions of the country. They are extensively used by locals as medicinal plants and a great negative selection pressure is applied on them. Therefore, due to importance of these plant species, we performed a population genetic study in both species. For this study, we used 66 randomly collected plants from 24 geographical populations of Helichrysum armenium and H. rubicundu. These species had areas of overlap and contact and we found some intermediate plants that were included in our study too. UPGMA and MDS analyses revealed morphological separation of these closely related species and placed intermediate plants in an intermediate position. ISSR analysis revealed inter-population genetic diversity and K-Means clustering and STRUCTURE analyses revealed populations. Genetic stratification in both species. Genetic difference of the studied populations was not correlated to geographical distance. Triangle plot of Bayesian analysis and NeighborNet plot showed inter-specific gene flow. The studied populations showed plants with 2n = 2x = 14 and 2n = 4x = 28 chromosomes and differed significantly in their meiotic behavior. Therefore, a combination of genetic stratification, and genetic admixture as well as polyploidy and chromosomes structural changes, have played rule in Helichrysum diversification.


2004 ◽  
Vol 7 (2) ◽  
pp. 180-186 ◽  
Author(s):  
M. Cohen ◽  
E. Cueto Rúa ◽  
N. Balcarce ◽  
R. Drut

Helicobacter pylori gastric infection induces structural changes in the gastric epithelium. Among them, variations in the expression of cytokeratins have been reported in adult patients. In the present study, we describe the expression of CK7 and CK20 in gastric samples taken from the antrum in three groups of pediatric patients: (A) Helicobacter pylori-associated chronic gastritis (mean age: 11.4 years); (B) previous H. pylori chronic gastritis patients (mean age: 9.4 years); and (C) controls (mean age: 8.8 years). In all, the presence of sulfomucins was assessed with Alcian blue-periodic acid-Schiff pH 1.0. Immunoreactivity was graded as absent (0), weak (1 +), moderate (2+), or intense (3+), in accordance with the intensity of the staining, and its distribution as focal or diffuse. CK7 reactivity was 2 + either focal or diffuse in all group A biopsies. The reactivity was more evident in the cells at the neck of the glands, in the areas with more inflammatory infiltrates, decorating long vertical segments of epithelium. In groups B and C, CK7 reactivity was also focal and 1 + at the cells of the necks of the glands. However, group B presented longer vertical segments of positive cells as compared to group C, and shorter than those of group A. The deeper glandular structures were focally 1 + in both groups. CK20 expression was comparable in all three groups, depicting a 2+ diffuse reactivity at the surface epithelium and interposed pits with absence or focal reactivity at the neck and coiled gland areas. Ki-67 immunostaining paralleled that of the CK7. Staining for sulfated mucosubstances was positive in two of five cases of groups A and B, and in none of the cases of group C. We conclude that: (1) the long segments of CK7-positive glandular necks in H. pylori cases most probably indicate intense regenerative activity during active inflammation; (2) eradication of H. pylori does not warrant ad integrum restitution since long segments of Ki-67+, CK7+ cells at the germinative compartment of the glands (as well as cells with sulfomucins) were still recognizable in ex- H. pylori patients; (3) finally, differing from what happens in adults, children somehow manage to maintain fully differentiated CK20+ superficial epithelium while the H. pylori is in action.


2018 ◽  
Author(s):  
Tarun Gupta ◽  
Sarah E. Howe ◽  
Marlo L. Zorman ◽  
Brent L. Lockwood

AbstractFighting between different species is widespread in the animal kingdom, yet this phenomenon has been relatively understudied in the field of aggression research. Particularly lacking are studies that test the effect of genetic distance, or relatedness, on aggressive behavior between species. Here we characterized male-male aggression within and between species of fruit flies across the Drosophila phylogeny. We show that male Drosophila discriminate between conspecifics and heterospecifics and show a bias for the target of aggression that depends on the genetic relatedness of opponent males. Specifically, males of closely related species treated conspecifics and heterospecifics equally, whereas males of distantly related species were overwhelmingly aggressive toward conspecifics. To our knowledge, this is the first study to quantify aggression between Drosophila species and to establish a behavioral bias for aggression against conspecifics versus heterospecifics. Our results suggest that future study of heterospecific aggression behavior in Drosophila is warranted to investigate the degree to which these trends in aggression among species extend to broader behavioral, ecological, and evolutionary contexts.


2019 ◽  
Vol 6 (6) ◽  
pp. 190069
Author(s):  
Tarun Gupta ◽  
Sarah E. Howe ◽  
Marlo L. Zorman ◽  
Brent L. Lockwood

Fighting between different species is widespread in the animal kingdom, yet this phenomenon has been relatively understudied in the field of aggression research. Particularly lacking are studies that test the effect of genetic distance, or relatedness, on aggressive behaviour between species. Here we characterized male–male aggression within and between species of fruit flies across the Drosophila phylogeny. We show that male Drosophila discriminate between conspecifics and heterospecifics and show a bias for the target of aggression that depends on the genetic relatedness of opponent males. Specifically, males of closely related species treated conspecifics and heterospecifics equally, whereas males of distantly related species were overwhelmingly aggressive towards conspecifics. To our knowledge, this is the first study to quantify aggression between Drosophila species and to establish a behavioural bias for aggression against conspecifics versus heterospecifics. Our results suggest that future study of heterospecific aggression behaviour in Drosophila is warranted to investigate the degree to which these trends in aggression among species extend to broader behavioural, ecological and evolutionary contexts.


2009 ◽  
Vol 17 (2) ◽  
pp. 42-45 ◽  
Author(s):  
Natalie Bauer ◽  
Jyoti Rai ◽  
Hairu Chen ◽  
Lillianne Harris ◽  
Lalita Shevde ◽  
...  

Microparticles and exosomes are small vesicular fragments of cell membrane which are released from activated and apoptotic cells. Microparticles (MPs) range in size from 0.5-1.5 μm, and exosomes are 0.5 μm and under. For the purposes of this article we will refer to both categories as microparticles. They differ from apoptotic bodies based on their smaller size, intact structure, and lack of degraded nuclear material. MPs have been shown to be released from a variety of cell types including platelets, endothelium, vascular smooth muscle cells, dendritic cells, and tumor cells. Jimenez and others have shown that based on the stimulus and cell type the MPs released are both quantitatively and phenotypically distinct. More recent data have shown the proteomics of MPs released from human umbilical vein endothelial cells differ dependent on whether they are stimulated with PAI or TNF-α.


2021 ◽  
Author(s):  
Matthew H. Van Dam ◽  
Analyn Anzano Cabras ◽  
Athena W. Lam

ABSTRACTThe evolutionary origins of mimicry in the Easter Egg weevil, Pachyrhynchus, have fascinated researchers since first noted more than a century ago by Alfred Russel Wallace. Müllerian mimicry, or mimicry in which two or more distasteful species look similar, is widespread throughout the animal kingdom. Given the varied but discrete color patterns in Pachyrhynchus, this genus presents one of the best opportunities to study the evolution of both perfect and imperfect mimicry. We analyzed more than 10,000 UCE loci using a novel partitioning strategy to resolve the relationships of closely related species in the genus. Our results indicate that many of the mimetic color patterns observed in sympatric species are due to convergent evolution. We suggest that this convergence is driven by frequency-dependent selection.


2021 ◽  
Author(s):  
Andrea Minio ◽  
Noe Cochetel ◽  
Amanda M Vondras ◽  
Melanie Massonnet ◽  
Dario Cantu

De novo genome assembly is essential for genomic research. High-quality genomes assembled into phased pseudomolecules are challenging to produce and often contain assembly errors caused by repeats, heterozygosity, or the chosen assembly strategy. Although algorithms exist that produce partially phased assemblies, haploid draft assemblies that may lack biological information remain favored because they are easier to generate and use. We developed HaploSync, a suite of tools that produces fully phased, chromosome-scale diploid genome assemblies and performs extensive quality control to limit assembly artifacts. HaploSync uses a genetic map and/or the genome of a closely related species to guide the scaffolding of a diploid assembly into phased pseudomolecules for each chromosome. It compares alternative haplotypes to identify and correct misassemblies independent of a reference, fills assembly gaps with unplaced sequences, and resolves collapsed homozygous regions. In a series of plant, fungal, and animal kingdom case studies, we demonstrate that HaploSync increases the assembly contiguity of phased chromosomes, improves completeness by filling gaps, corrects scaffolding, and correctly phases highly heterozygous, complex regions.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Chuanfu Dong ◽  
Cameron J Weadick ◽  
Vincent Truffault ◽  
Ralf J Sommer

The small molecules that mediate chemical communication between nematodes—so-called ‘nematode-derived-modular-metabolites’ (NDMMs)—are of major interest because of their ability to regulate development, behavior, and life-history. Pristionchus pacificus nematodes produce an impressive diversity of structurally complex NDMMs, some of which act as primer pheromones that are capable of triggering irreversible developmental switches. Many of these NDMMs have only ever been found in P. pacificus but no attempts have been made to study their evolution by profiling closely related species. This study brings a comparative perspective to the biochemical study of NDMMs through the systematic MS/MS- and NMR-based analysis of exo-metabolomes from over 30 Pristionchus species. We identified 36 novel compounds and found evidence for the convergent evolution of complex NDMMs in separate branches of the Pristionchus phylogeny. Our results demonstrate that biochemical innovation is a recurrent process in Pristionchus nematodes, a pattern that is probably typical across the animal kingdom.


1966 ◽  
Vol 14 (5) ◽  
pp. 821 ◽  
Author(s):  
MJD White ◽  
J Cheney

Two closely related species belonging to the cultrata group show an XY condition in the male as a result of an X-autosome fusion. One of these has two cytological races which differ in the shape of the Y chromosome. This complex of XY forms has given rise to an XlX2Y species by a further Y-autosome fusion. The latter species has two cytological races which differ in the shape of the Y and X2 chromosomes, presumably as a result of the fixation of pericentric inversions and other structural changes.


Author(s):  
Agnes Kelly

In the course of an investigation on calcareous secretions in the animal kingdom, and more particularly on molluscan shells, I found that the latter did not consist of aragonite, as G. Rose and Sorby had supposed, but of a negative, uniaxial mineral, which is distinguished by most of its properties from calcite, and for which I propose the name conchite (KóγXη, shell). I further found that conehite occurred naturally in many localities--always as a crystal aggregate. Its properties were investigated on such, as well as on the eonchite in shells.


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