Universities in Developmental Transition

This chapter interrogates the benefits that would accrue to and challenges faced by universities in their developmental transition from being an ivory tower to engaged and people-centered institutions. The chapter argues that universities should consider themselves as vehicles of socio-economic change by participating in the process of forming values and setting reachable goals for the benefit of larger society. University of Botswana (UB) adopted ‘Strategy for Excellence: University of Botswana Strategic Plan to 2016 and Beyond' while the University of KwaZulu-Natal has adopted Strategic Plan 2017-2021 with eight goals. Through these plans, the universities seek to have a more direct impact within communities and society. Community engagement or service learning is adopted as one of the vehicles to fast-track the transition process in this chapter. This chapter is qualitative and has made use of UB and UKZN as the case studies to deliberate the university transition from ivory towers into engaged, responsible, and people-centered institutions.

Histone H3K27 methylation–mediated repression of Hairy regulates insect developmental transition by modulating ecdysone biosynthesis

Insect development is cooperatively orchestrated by the steroid hormone ecdysone and juvenile hormone (JH). The polycomb repressive complex 2 (PRC2)–mediated histone H3K27 trimethylation (H3K27me3) epigenetically silences gene transcription and is essential for a range of biological processes, but the functions of H3K27 methylation in insect hormone action are poorly understood. Here, we demonstrate that H3K27 methylation–mediated repression of Hairy transcription in the larval prothoracic gland (PG) is required for ecdysone biosynthesis in Bombyx and Drosophila. H3K27me3 levels in the PG are dynamically increased during the last larval instar. H3K27me3 reduction induced by the down-regulation of PRC2 activity via inhibitor treatment in Bombyx or PG-specific knockdown of the PRC2 component Su(z)12 in Drosophila diminishes ecdysone biosynthesis and disturbs the larval–pupal transition. Mechanistically, H3K27 methylation targets the JH signal transducer Hairy to repress its transcription in the PG; PG-specific knockdown or overexpression of the Hairy gene disrupts ecdysone biosynthesis and developmental transition; and developmental defects caused by PG-specific Su(z)12 knockdown can be partially rescued by Hairy down-regulation. The application of JH mimic to the PG decreases both H3K27me3 levels and Su(z)12 expression. Altogether, our study reveals that PRC2-mediated H3K27 methylation at Hairy in the PG during the larval period is required for ecdysone biosynthesis and the larval–pupal transition and provides insights into epigenetic regulation of the crosstalk between JH and ecdysone during insect development.

Developmental increase of inhibition drives decorrelation of neural activity

Throughout development, the brain transits from early highly synchronous activity patterns to a mature state with sparse and decorrelated neural activity, yet the mechanisms underlying this process are unknown. The developmental transition has important functional consequences, as the latter state allows for more efficient storage, retrieval and processing of information. Here, we show that, in the mouse medial prefrontal cortex (mPFC), neural activity during the first two postnatal weeks decorrelates following specific spatial patterns. This process is accompanied by a concomitant tilting of excitation/inhibition (E-I) ratio towards inhibition. Using optogenetic manipulations and neural network modeling, we show that the two phenomena are mechanistically linked, and that a relative increase of inhibition drives the decorrelation of neural activity. Accordingly, in two mouse models of neurodevelopmental disorders, subtle alterations in E-I ratio are associated with specific impairments in the correlational structure of spike trains. Finally, capitalizing on EEG data from newborn babies, we show that an analogous developmental transition takes place also in the human brain. Thus, changes in E-I ratio control the (de)correlation of neural activity and, by these means, its developmental imbalance might contribute to the pathogenesis of neurodevelopmental disorders.

Integration of embryo-endosperm interaction into a holistic and dynamic picture of seed development using a rice mutant with notched-belly grains

ABSTRACTThe interaction between the embryo and endosperm affects seed development, an essential process in yield formation in crops such as rice. Signals that communicate between embryo and endosperm are largely unknown. Here we use the notched-belly (NB) mutant with impaired communication between embryo and endosperm to evaluate 1) the impact of embryo on developmental staging of the endosperm; 2) signaling pathways emanating from the embryo that regulate endosperm development. Hierachical clustering of mRNA datasets from embryo and endosperm samples collected through development in NB and wild type showed a delaying effect of the embryo on the developmental transition of the endosperm by extending the middle stage. K-means clustering further identified coexpression modules of gene sets specific for embryo and endosperm development. Combined gene expression and biochemical analysis showed that T6P-SnRK1, gibberellin and auxin signalling from the embryo regulate endosperm developmental transition. The data enable us to propose a new seed developmental staging system for rice and the most detailed signature of rice grain formation to date, that will direct genetic strategies for rice yield improvement.

A daf-7-related TGF-β ligand (Hc-tgh-2) shows important regulations on the development of Haemonchus contortus

Background In most multicellular organisms, transforming growth factor-β (TGF-β) signalling pathway is involved in regulating the growth and stem cell differentiation. Previous studies have demonstrated the importance of three key molecules in this pathway in the parasitic nematode Haemonchus contortus , including one TGF-β type I receptor ( Hc-tgfbr1 ), one TGF-β type II receptor ( Hc-tgfbr2 ), and one co-Smad ( Hc-daf-3 ), which regulated the developmental transition from the free-living to the parasitic stages of this parasite. However, almost nothing is known about the function of the TGF-β ligand ( Hc-tgh-2 ) of H. contortus . Methods Here, the temporal transcription profiles of Hc-tgh-2 at eight different developmental stages and spacial expression patterns of Hc- TGH-2 in adult female and male worms of H. contortus have been examined by real-time PCR and immunohistochemistry, respectively. In addition, RNA interference (RNAi) by soaking was employed to assess the importance of Hc-tgh-2 in the development from exsheathed third-stage larvae (xL3s) to fourth-stage larvae (L4s) in H. contortus . Results Hc-tgh-2 was continuously transcribed in all eight developmental stages of H. contortus studied with the highest level in the infective third-stage larvae (iL3) and Hc -TGH-2 was located in the muscle of the body wall, intestine, ovary of adult females and testes of adult males. Silencing Hc-tgh-2 by the specific double-stranded RNA (dsRNA), decreased the transcript level of Hc-tgh-2 and resulted in fewer xL3s developing to L4s in vitro. Conclusions These results suggested that the TGF-β ligand, Hc -TGH-2, could play important roles in the developmental transition from the free-living (L3s) to the parasitic stage (L4s). Furthermore, it may also take part in the processes such as digestion, absorption, host immune response and reproductive development in H. contortus adults.

A daf-7-related TGF-β ligand (Hc-tgh-2) shows important regulations on the development of Haemonchus contortus

Background In most multicellular organisms, transforming growth factor-β (TGF-β) signalling pathway is involved in regulating the growth and stem cell differentiation. Previous studies have demonstrated the importance of three key molecules in this pathway in the parasitic nematode Haemonchus contortus , including one TGF-β type I receptor ( Hc-tgfbr1 ), one TGF-β type II receptor ( Hc-tgfbr2 ), and one co-Smad ( Hc-daf-3 ), which regulated the developmental transition from the free-living to the parasitic stages of this parasite. However, almost nothing is known about the function of the TGF-β ligand ( Hc-tgh-2 ) of H. contortus . Methods Here, the temporal transcription profiles of Hc-tgh-2 at eight different developmental stages and spacial expression patterns of Hc- TGH-2 in adult female and male worms of H. contortus have been examined by real-time PCR and immunohistochemistry, respectively. In addition, RNA interference (RNAi) by feeding was employed to assess the importance of Hc-tgh-2 in the development from exsheathed third-stage larvae (xL3s) to fourth-stage larvae (L4s) in H. contortus . Results Hc-tgh-2 was continuously transcribed in all eight developmental stages of H. contortus studied with the highest level in the infective third-stage larvae (iL3) and Hc -TGH-2 was located in the muscle of the body wall, intestine, ovary of adult females and testes of adult males. Silencing Hc-tgh-2 by the specific double-stranded RNA (dsRNA), decreased the transcript level of Hc-tgh-2 and resulted in fewer xL3s developing to L4s in vitro. Conclusions These results suggested that the TGF-β ligand, Hc -TGH-2, could play important roles in the developmental transition from the free-living (L3s) to the parasitic stage (L4s). Furthermore, it may also take part in the processes such as digestion, absorption, host immune response and reproductive development in H. contortus adults.