Background: In amphibians, thyroid hormone (TH) has a profound role in cranial development, especially in ossification of the late-appearing bones and remodeling of the skull. In the present study, we explored the influence of TH deficiency on bone ossification and resulting skull shape during the ontogeny of newt hybrid larvae obtained from interspecific crosses between and .
Methods: Larvae were treated with two concentrations of thiourea (an endocrine disruptor that chemically inhibits synthesis of TH) during the midlarval and late larval periods. Morphological differences of the cranium were assessed at the end of the midlarval period (ontogenetic stage 62) and the metamorphic stage after treatment during the late larval period.
Results: There was no difference in the ossification level and shape of the skull between the experimental groups (control and two treatment concentrations) at stage 62. During the late larval period and metamorphosis, TH deficit had a significant impact on the level of bone ossification and skull shape with no differences between the two treatment concentrations of thiourea. The most pronounced differences in bone development were: the palatopterygoid failed to disintegrate into the palatal and pterygoid portions, retardation was observed in development of the maxilla, nasal and prefrontal bones and larval organization of the vomer was retained in thiourea-treated larvae.
Conclusions: This implies that deficiency of TH caused retardation in development and arrested metamorphic cranium skeletal reorganization, which resulted in divergent cranial shape compared to the control group. Our results confirmed that skull remodeling and ossification of late-appearing bones is TH-dependent, as in other studied Urodela species. Also, our results indicate that TH plays an important role in the establishment of skull shape during the ontogeny of newts, especially during the late larval period and metamorphosis, when TH concentrations reach their maximum.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8179219 | PMC |
http://dx.doi.org/10.7717/peerj.11535 | DOI Listing |
Insects
January 2025
Zoological Institute, Russian Academy of Sciences, Universitetskaya 1, 199034 St. Petersburg, Russia.
Insect diapause and response to thermal stress are similar in the variety of manifestations. However, the influence of thermal shocks on the incidence of insect diapause has not been sufficiently studied. Our laboratory experiments showed that both cold (-10 °C) and heat (43 °C) shocks experienced for at least 20-30 min significantly reduced the incidence of facultative larval winter diapause in the insect egg parasitoid .
View Article and Find Full Text PDFJ Econ Entomol
January 2025
Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE, USA.
The invasive emerald ash borer (Agrilus planipennis Fairmaire) (EAB) has been devastating North American ash (Fraxinus spp.) resources for over 2 decades. In its native range, EAB attacks and kills primarily stressed ash trees.
View Article and Find Full Text PDFGerms
September 2024
MD, PhD, Infectious Diseases Department, University Hospital of Split, HR-21000 Split, Croatia, and University of Split School of Medicine, HR-21000 Split, Croatia, and University Department of Health Studies of the University of Split, HR-21000 Split, Croatia.
Introduction: Alveolar echinococcosis is one of the most pathogenic zoonoses caused by the larval forms of . It is endemic in central Europe, but from 2001 to 2018, eight European countries reported their first cases of alveolar echinococcosis. These numbers testify to unprecedented spread of the infection.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
Universidade da Coruña, Grupo NanoToxGen, Centro Interdisciplinar de Química e Bioloxía - CICA, Departamento de Biología, Facultad de Ciencias, Campus A Zapateira s/n, A Coruña 15071, Spain; Instituto de Investigación Biomédica de A Coruña (INIBIC), Complexo Hospitalario Universitario de A Coruña (CHUAC), Sergas, As Xubias, A Coruña 15006, Spain. Electronic address:
Nanoceria, or cerium dioxide nanoparticles (CeO NP), are increasingly employed in a number of industrial and commercial applications. Hence, the environmental presence of these nanoparticles is growing progressively, enhancing the global concern on their potential health effects. Recent studies suggest that nanoceria may also have promising biomedical applications particularly in neurodegenerative and brain-related pathologies, but studies addressing their toxicity, and specifically on the nervous system, are still scarce, and their potential adverse effects and action mechanism are not totally understood yet.
View Article and Find Full Text PDFSci Rep
January 2025
College of Life and Health Science, Kaili University, Kaili, 556011, P. R. China.
The fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae) is a major phytophagous pest that invaded China in late 2018, posing a serious threat to local agricultural production. Therefore, we investigated the effects of maize, soybean, and sweet potato on the growth, development, and reproduction of S. frugiperda under laboratory conditions.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!