Telomerase as a possible key to bypass the cost of reproduction effect

Telomerase activity and telomere restoration in certain somatic cells of human adults maintain the proliferative capacity of these cells and contribute to their regenerative potential, and telomerase activity and telomere length are commonly considered lifespan predictors. Eusocial insects provide excellent model systems for aging research based on their extraordinary caste-related lifespan differences that contradict the typical fecundity/lifespan trade-off. In agreement with the common presumption, telomerase activity is upregulated in the reproductive, long-lived individuals of eusocial insects such as queens and kings, proposing that telomerase activity acts as a key factor in their extended longevity. But, as documented by the presence of telomerase in somatic tissues of numerous invertebrate and vertebrate species, the connection between telomerase activity and the predicted lifespan is not clear. Here, I ask whether somatic telomerase activity in eusocial reproductives may serve its non-canonical function to protect its individuals against the exacerbated metabolic stress upon reproduction and be a reflection of a more common phenomenon among species. I propose a hypothesis that the presence of telomerase activity in somatic cells reflects a different reproduction strategy of the species.

REPRODUCTIVE ASPECTS OF JAGUAR (PANTHERA ONCA): FEMALE

Objective: Describe the reproductive characteristics of the female jaguar as well as assisted reproduction techniques. Design/methodology/approach: A literature review about reproductive characteristics and assisted reproduction techniques was done to documented information about it. Results: The Jaguar is considered the largest feline in America, females are 1.57 to 2.19 m of length and weigh 45 to 82 kg. The jaguar female is ready for mating when it is about 2 years old. Regarding the estrous cycle, it is divided into: proestrus, estrus, diestrous, interestrous and anestrus. Environment influence on the reproductive behavior of the jaguar, being the steroids those that stimulate the production of pheromones to attract the male; in the female the secretion is cyclical. The gestation lasts approximately between 90 and 110 days and they usually give birth to 1 or up to 4 young. In the case of assisted reproduction, artificial insemination could be useful to preserve genetic material from animals with outstanding characteristics. Limitations on study/implications: The destruction of forests and jungles, the fragmentation of habitat, indiscriminate hunting, the lack of prey as a food source and the conflict with ranchers has put the Jaguar on the brink of extinction, in addition there is little information about its reproductive characteristics, which is why in Mexico, it is imperative to generate this information, mainly in free-living jaguar. Findings/conclusions: Reproductive characteristics of jaguar female were documented from a literature review as well as assisted reproduction techniques. Knowledge of these will allow developed reproductive strategies to work on a national conservation and reproduction strategy to preserve the species.

Maintenance of quiescent oocytes by noradrenergic signals

All females adopt an evolutionary conserved reproduction strategy; under unfavorable conditions such as scarcity of food or mates, oocytes remain quiescent. However, the signals to maintain oocyte quiescence are largely unknown. Here, we report that in four different species – Caenorhabditis elegans, Caenorhabditis remanei, Drosophila melanogaster, and Danio rerio – octopamine and norepinephrine play an essential role in maintaining oocyte quiescence. In the absence of mates, the oocytes of Caenorhabditis mutants lacking octopamine signaling fail to remain quiescent, but continue to divide and become polyploid. Upon starvation, the egg chambers of D. melanogaster mutants lacking octopamine signaling fail to remain at the previtellogenic stage, but grow to full-grown egg chambers. Upon starvation, D. rerio lacking norepinephrine fails to maintain a quiescent primordial follicle and activates an excessive number of primordial follicles. Our study reveals an evolutionarily conserved function of the noradrenergic signal in maintaining quiescent oocytes.

Ontogeny, evolution and palaeogeographic distribution of the world’s largest ammonite Parapuzosia (P.) seppenradensis (Landois, 1895)

The world’s largest ammonite, Parapuzosia (P.) seppenradensis (Landois, 1895), fascinated the world ever since the discovery, in 1895, of a specimen of 1.74 metres (m) diameter near Seppenrade in Westfalia, Germany, but subsequent findings of the taxon are exceedingly rare and its systematic position remains enigmatic. Here we revise the historical specimens and document abundant new material from England and Mexico. Our study comprises 154 specimens of large (< 1 m diameter) to giant (> 1m diameter) Parapuzosia from the Santonian and lower Campanian, mostly with stratigraphic information. High-resolution integrated stratigraphy allows for precise cross-Atlantic correlation of the occurrences. Our specimens were analysed regarding morphometry, growth stages and stratigraphic occurrence wherever possible. Our analysis provides insight into the ontogeny of Parapuzosia (P.) seppenradensis and into the evolution of this species from its potential ancestor P. (P.) leptophylla Sharpe, 1857. The latter grew to shell diameters of about 1 m and was restricted to Europe in the early Santonian, but it reached the Gulf of Mexico during the late Santonian. P. (P.) seppenradensis first appears in the uppermost Santonian- earliest Campanian on both sides of the Atlantic. Initially, it also reached diameters of about 1 m, but gradual evolutionary increase in size is seen in the middle early Campanian to diameters of 1.5 to 1.8 m. P. (P.) seppenradensis is characterized by five ontogenetic growth stages and by size dimorphism. We therefore here include the many historic species names used in the past to describe the morphological and size variability of the taxon. The concentration of adult shells in small geographic areas and scarcity of Parapuzosia in nearby coeval outcrop regions may point to a monocyclic, possibly even semelparous reproduction strategy in this giant cephalopod. Its gigantism exceeds a general trend of size increase in late Cretaceous cephalopods. Whether the coeval increase in size of mosasaurs, the top predators in Cretaceous seas, caused ecological pressure on Parapuzosia towards larger diameters remains unclear.

Successful captive breeding of a Malayan pangolin population to the third filial generation

Pangolins are threatened placental mammals distributed in Africa and Asia. Many efforts have been undertaken in the last century to maintain pangolins in captivity, but only a few of them succeeded in maintaining and keeping this species in a controlled environment. This study reports the first systematic breeding of the Critically Endangered Malayan pangolin (Manis javanica) in captivity. Our captive breeding approach successfully improved the reproductive rate for both wild and captive-born female pangolins. From 2016 to 2020, we had 33 wild pangolins and produced 49 captive-born offspring spanning three filial generations. The female offspring further bred 18 offspring, of which 14 (78%) were conceived during the first time of cohabitation with males, and four offspring were conceived during the second cohabitation event, suggesting that they may practice copulation-induced ovulation. We observed that captive-born female pangolins could reach sexual maturity at 7–9 months (n = 4), and male pangolins could mate and successfully fertilise females at nine months age (n = 1). We also observed a female pangolin conceiving on the eighth day after parturition (the fifth day after the death of its pup). Our captive pangolins had a female-biased sex ratio of 1:0.5 at birth, unlike other known captive-born mammals. Also, captive-born pangolins were generally more viable after successful weaning and had a similar gestation length (~185 days) to wild pangolins. Most importantly, we report the first self-sustaining captive population of Malayan pangolins, and this species has an efficient reproduction strategy. These advances provide more comprehensive information for people to understand pangolins, and have implications for conserving endangered Malayan pangolins and providing scientific guidance to the management of other pangolin species.

Emergence of a new salt-tolerant alien grass along roadsides? Occurrence of Diplachne fusca subsp. fascicularis (Poaceae) in Hungary

This paper reports the occurrence of a North American salt-tolerant taxon, Diplachne fusca subsp. fascicularis (Lam.) P.M.Peterson et N.Snow in Hungary (Central-Europe). Two earlier Hungarian observations of D. fusca were known from 1915, near Győr (West Transdanubia), later the taxon was collected by Pénzes in 1958, in downtown Budatétény (central Hungary. Both observations seem to be occasional. Recently, the taxon has started spreading in Europe, mainly on rice paddy fields, with a serious invasion potential. In North America its appearance on ruderal habitats, as well as along roads and other linear infrastructures is a well known phenomenon. The Hungarian population was found near Cegléd (Central Hungary) on the roadside of the E40 primary main road in September 2018. In July 2019 more than one thousand (mostly vegetative) individuals were detected. The salt content of the habitat shows remarkable temporal and spatial variability. At one meter distance from the edge of the paved road soil salt content was higher in spring (after the winter de-icing regime), than in autumn. Salt concentration was highest in the vicinity of the road, and decreased with increasing distance from it. Germination tests revealed a significant negative effect of NaCl concentration on germination rates, but germination occurred even on extremely saline substrates with 1.5% NaCl concentration. Considering its biology and reproduction strategy, the further spread of Diplachne fusca is highly presumable.

Polyp dropout in a solitary cold-water coral

Scleractinian corals feature both sessile and mobile stages and diverse modes of development. In some cases, development can be reversed. Examples include polyp detachment in response to environmental stress (bail-out or polyp expulsion) and reverse metamorphosis, where juveniles detach from the primary skeleton and revert to the mobile stage. Here, we provide aquaria and field evidence of a new form of reverse development: polyp dropout in the solitary cold-water coral Caryophyllia huinayensis. It features tissue retraction and detachment of an entire adult polyp from the skeleton in the putative absence of a stressor. The dropout polyp remains viable and continues to live for many weeks, albeit in a rather collapsed state lacking a well-developed hydroskeleton. We carried out a long-term (37 months) rearing experiment under constant aquaria conditions and found polyp dropout in four out of 83 individuals. Detachment was accompanied by the extrusion of mesenterial filaments through perforations in the body wall. We believe this resulted in the loss of the hydroskeleton, which prevented the dropouts to subsequently resettle or form a new skeleton. As opposed to other known forms of reverse development, the new form is not accompanied by reversible metamorphosis, abandonment of the colonial way of life, nor is it a survival or asexual reproduction strategy. We found field indications of polyp dropout in Patagonian field populations of C. huinayensis, where 1.4 ± 0.8% (mean ± SD, N = 9322) of the polyps of the natural population showed partial detachment indicative of imminent dropout in the putative absence of external impact. Polyp dropout is the first record of polyp detachment in a solitary CWC with possible repercussions for adult coral mobility, evolution and Stanley’s (2003) ‘naked coral’ hypothesis.

Optimization of Teaching Evaluation System for Football Professional Teachers Based on Multievaluation Model

The introduction of multiple intelligence theory into sports professional football teaching is a requirement of educational innovation, which helps to expand and play the multiple functions of football, and can effectively improve the comprehensive quality of football professional science. Under the perspective of multiple intelligence theory, college sports professional football teaching will focus on the all-round development of students, actively cultivate students’ multiple intelligence, and reflect the democratization, individualization, and diversification of teaching in the process of educational concept innovation. This article explains the origin and characteristics of the particle swarm optimization algorithm and discusses the application status of the PSO algorithm in detail. We introduced the standard PSO algorithm, including mathematical forms, iteration steps, and flowcharts. In addition, it also specifically describes the proposed new PSO improved algorithm, including the food chain strategy and reproduction strategy, as well as the implementation of the algorithm. Through analysis, it is concluded that the implementation and implementation of relevant systems is the guarantee for the sustained and sound development of campus football. The amount of football lessons is insufficient, and the classroom teaching effect is not ideal. Physical education teachers are acceptable, but the football professional knowledge training of physical education teachers needs to be strengthened. The selection and setting of the teaching content of football lessons lack systematic, scientific, and adaptable, and the teaching methods and teaching model concepts are backward. In the process of football teaching, teachers ignored the evaluation and assessment of students’ nonphysical and nonintellectual factors, and campus football activities did not achieve the expected goals.

Reproduction as a Means of Evaluating Policy Models: A Case Study of a COVID-19 Simulation

This article proposes (and demonstrates the effectiveness of) a new strategy for assessing the results of epidemic models which we designate reproduction. The strategy is to build an independent model that uses (as far as possible) only the published information about the model to be assessed. In the example presented here, the independent model also follows a different modelling approach (agent-based modelling) to the model being assessed (the London School of Hygiene and Tropical Medicine compartmental model which has been influential in COVID lockdown policy). The argument runs that if the policy prescriptions of the two models match then this independently supports them (and reduces the chance that they are artefacts of assumptions, modelling approach or programming bugs). If, on the other hand, they do not match then either the model being assessed is not provided with sufficient information to be relied on or (perhaps) there is something wrong with it. In addition to justifying the approach, describing the two models and demonstrating the success of the approach, the article also discusses additional benefits of the reproduction strategy independent of whether match between policy prescriptions is actually achieved.