Protocol of Geometric Morphometrics for Teratogenicity Testing

Geometric morphometrics (GM) enables a quantitative study of shapes and forms allowing the identification and characterization of teratogenic malformations. The GM methodology offers several advantages in comparison to traditional biometric methods, such as higher detail and precision analysis. In this chapter, we describe the recent application of the Procrustes method with ImageJ and MorphoJ programs in the characterization of developmental malformations. With this methodology, we are a step closer to being able to assign molecular pathways or unique signatures to a specific teratogen according to the produced phenotypes or to cluster unknown compounds.

Augmented impulsive behavior in febrile seizure-induced mice

Febrile seizure (FS) is one of the most prevalent etiological events in childhood affecting 2-5% of children from 3 months to 5 years old. Debates on whether neurodevelopmental consequences rise in later life following a febrile seizure or not are still ongoing however there is limited evidence of its effect, especially in a laboratory setting. Moreover, the comparative study using both male and female animal models is sparse. To examine the effect of FS on the behavioral features of mice, both sexes of ICR mice were induced with hyperthermic seizures through exposure to an infrared heat lamp. The mice were divided into two groups, one receiving a single febrile seizure at postnatal day 11 (P11) and one receiving three FS at P11, P13, and P15. Starting at P30 the FS-induced mice were subjected to a series of behavioral tests. Mice with seizures showed no locomotor and motor coordination deficits, repetitive, and depressive-like behavior. However, the FS-induced mice showed impulsive-like behavior in both elevated plus maze and cliff avoidance tests, which is more prominent in male mice. A greater number of mice displayed impaired CAT in both males and females in the three-time FS-induced group compared to the single induction group. These results demonstrate that after induction of FS, male mice have a higher susceptibility to consequences of febrile seizure than female mice and recurrent febrile seizure has a higher chance of subsequent disorders associated with decreased anxiety and increased impulsivity. We confirmed the dysregulated expression of impulsivity-related genes such as 5-HT1A and tryptophan hydroxylase 2 from the prefrontal cortices of FS-induced mice implying that the 5-HT system would be one of the mechanisms underlying the increased impulsivity after FS. Taken together, these findings are useful in unveiling future discoveries about the effect of childhood febrile seizure and the mechanism behind it.

The role of social isolation stress in escalated aggression in rodent models

Anti-social behavior and violence are major public health concerns. Globally, violence contributes to more than 1.6 million deaths each year. Previous studies have reported that social rejection or neglect exacerbates aggression. In rodent models, social isolation stress is used to demonstrate the adverse effects of social deprivation on physiological, endocrinological, immunological, and behavioral parameters, including aggressive behavior. This review summarizes recent rodent studies on the effect of social isolation stress during different developmental periods on aggressive behavior and the underlying neural mechanisms. Social isolation during adulthood affects the levels of neurosteroids and neuropeptides and increases aggressive behavior. These changes are ethologically relevant for the adaptation to changes in local environmental conditions in the natural habitats. Chronic deprivation of social interaction after weaning, especially during the juvenile to adolescent periods, leads to the disruption of the development of appropriate social behavior and the maladaptive escalation of aggressive behavior. The understanding of neurobiological mechanisms underlying social isolation-induced escalated aggression will aid in the development of therapeutic interventions for escalated aggression.

Intergenerational Transmission of Peer Aggression

It is plausible that peer aggression—like general forms of aggression—is transmitted from one generation to the next. As such, parental behavior in childhood and adolescence may be associated with offspring aggressive behavior against peers. This study used 1970 British Cohort Study data to test intergenerational transmission of peer aggression. The baseline sample consisted of 13,135 participants. At the first assessment that was used in this study, participants were on average 4.95 years old (SD = 0.79; 48.20% female). At the last assessment, participants were on average 33.88 years old (SD = 0.36; 52.1% female). Models were computed for early and middle childhood, and adolescence. Significant associations between parents’ and offspring peer aggression were found in most models – especially when correlating aggression in similar developmental periods for parents and children. Other transmission mechanisms such as genetic transmission may be relevant and should be taken into account in future studies.

Analyses of key gene networks controlling carotenoid metabolism in Xiangfen 1 banana

BACKGROUND

Banana fruits are rich in various high-value metabolites and play a key role in the human diet. Of these components, carotenoids have attracted considerable attention due to their physiological role and human health care functions. However, the accumulation patterns of carotenoids and genome-wide analysis of gene expression during banana fruit development have not been comprehensively evaluated.

RESULTS

In the present study, an integrative analysis of metabolites and transcriptome profiles in banana fruit with three different development stages was performed. A total of 11 carotenoid compounds were identified, and most of these compounds showed markedly higher abundances in mature green and/or mature fruit than in young fruit. Results were linked to the high expression of carotenoid synthesis and regulatory genes in the middle and late stages of fruit development. Co-expression network analysis revealed that 79 differentially expressed transcription factor genes may be responsible for the regulation of LCYB (lycopene β-cyclase), a key enzyme catalyzing the biosynthesis of α- and β-carotene.

CONCLUSIONS

Collectively, the study provided new insights into the understanding of dynamic changes in carotenoid content and gene expression level during banana fruit development.

Jackdaw nestlings rapidly increase innate immune function during the nestling phase but no evidence for a trade-off with growth

Although animals are born with a protective immune system, even the innate immune system is under development from birth to adulthood and this development may be affected by sex and growth. However, most knowledge comes from captive animals or long-lived slow growing species. Moreover, little is known about how innate immune function, the important first line of defence, develops during early life in fast-growing animals such as free-living passerines. We studied development of innate baseline immune function in nestlings of free-living jackdaws Corvus monedula. We measured four immune parameters (hemolysis, hemagglutination, bacterial-killing capacity, haptoglobin concentration) and structural body size (body mass, wing length, tarsus length) at day 12 and day 29 post-hatching. We found that three out of four immune parameters (hemolysis, hemagglutination, bacterial-killing capacity) substantially increased with nestling age and had roughly reached adult levels shortly prior to fledging. We found little differences in immune development between males and females despite them differing in structural development. We also found no evidence that the nestlings traded off immune development with growth. That nestlings rapidly increase innate baseline immune function during early life and similarly in males and females indicates the importance of a well-functioning immune system already during the nestling phase.

Assessing cancer risk factors faced by an Ancestral Puebloan population in the North American Southwest

Ancestral Puebloan people in the North American Southwest suffered high rates of disease, poor health, and early age-at-death. Four individuals with skeletal expressions of cancer were found in a pre-Columbian population in the Taos Valley - Reports of malignant neoplasms in the archaeological record are uncommon and their presence in four of 82 individuals is a high occurrence. This study continues Whitley and Boyer's (2012) research testing whether concentrations of ionizing radiation were sufficiently high to induce cancer and related health issues. Access to a preserved and partly reconstructed subterranean pit structure inhabited between AD 1120 and 1170, allows us to test radon concentrations in a residential dwelling. This study found radon occurring in high levels, 19.4-20.3 pCi/L (717.8-751.1 Bq/m3) within the structure. Epidemiological reports are inconsistent when linking specific cancers and radon exposure. However, this study can control for many of the confounding factors plaguing other studies, provide unique data that have the potential to initiate dialogue on the etiology of neoplastic disease in the American Southwest, and add new dimensions to the study of the living conditions and health of the Ancestral Puebloans and their descendants.

Developmental study of rectum in broiler chicken: A stereological and morphometrical study

The objective of this study was to investigate development of the weight and the morphological development of the rectum in broiler chickens. Twenty broiler chickens (Ross 308) were used in this experiment and they were 12, 20, 35 and 44 days of age. Samples from the rectum of chicks were sectioned in an unbiased manner and examined quantitatively using stereology. In addition, the weight of both body (BW) and rectum and also rectum weight as a proportion of BW, height and width of the villi and thickness of rectum wall were measured. The results revealed that the body and rectum weight were increased with age. The greatest rectum weight as a proportion of BW was observed on day 20. An increase in height and width of the villi during the study period were obtained. The increase was more significant on days 35 and 44 than on days 12 and 20 (p < 0.05). There were significant difference in thickness of tunica mucosa, submucosa and muscular layer of the rectum on day 20 compared to day 35 (p < 0.05). The increase in the volume density of the wall, tunica mucosa and tunica muscular was greater on day 20 than on day 35. However, significant differences were observed in volume density of this layers between days 35 and 44 compared to days 12 and 20 (p < 0.05).

The developmental effects of extremely low frequency electric fields on visual and somatosensory evoked potentials in adult rats

The purpose of our study was to investigate the developmental effects of extremely low frequency electric fields (ELF-EFs) on visual evoked potentials (VEPs) and somatosensory-evoked potentials (SEPs) and to examine the relationship between lipid peroxidation and changes of these potentials. In this context, thiobarbituric acid reactive substances (TBARS) levels were determined as an indicator of lipid peroxidation. Wistar albino female rats were divided into four groups; Control (C), gestational (prenatal) exposure (Pr), gestational+ postnatal exposure (PP) and postnatal exposure (Po) groups. Pregnant rats of Pr and PP groups were exposed to 50 Hz electric field (EF) (12 kV/m; 1 h/day), while those of C and Po groups were placed in an inactive system during pregnancy. Following parturition, rats of PP and Po groups were exposed to ELF-EFs whereas rats of C and Pr groups were kept under the same experimental conditions without being exposed to any EF during 68 days. On postnatal day 90, rats were prepared for VEP and SEP recordings. The latencies of VEP components in all experimental groups were significantly prolonged versus C group. For SEPs, all components of PP group, P2, N2 components of Pr group and P1, P2, N2 components of Po group were delayed versus C group. As brain TBARS levels were significantly increased in Pr and Po groups, retina TBARS levels were significantly elevated in all experimental groups versus C group. In conclusion, alterations seen in evoked potentials, at least partly, could be explained by lipid peroxidation in the retina and brain.