Summary During the earliest division stages, zebrafish embryos have large cells that divide rapidly and synchronously to create a cellular layer on top of the yolk. Here, we describe a protocol for monitoring spindle dynamics during these early embryonic divisions. We outline techniques for injecting zebrafish embryos with small-molecule inhibitors toward polo-like kinases, preparing and mounting embryos for three-dimensional imaging using confocal microscopy. These techniques are used to understand how the early zebrafish embryo’s centrosome constructs the mitotic spindle. For complete details on the use and execution of this protocol, please refer to Rathbun et al. (2020) .

The centrosome protein, cenexin, C terminus acts in a conserved manner in eukaryotes to anchor PLK1, moderating its potential to phosphorylate PCM substrates required for PCM integrity and function.

Breastfeeding is the optimal method of infant feeding bringing short-and long-term benefits for infants, mothers, environment, economy and the entire society. A variety of factors influence and determine breastfeeding duration, including characteristics of the mother, the child and the family, aspects of the health care system, public health and social policies, advertising and promotion of alternative feeding methods. This study aimed to investigate the factors which are associated with breastfeeding duration in a sample of mothers living in Sarajevo Canton, Bosnia and Herzegovina. This cross-sectional study was carried out at the Pediatric Outpatient Department of the Public Institution Primary Health Care Centre of Canton Sarajevo. The study evaluated 150 mothers in three groups according to breastfeeding duration of 50 each (i.e. less than 3 months, 3–5 months and 6 months and more). As an instrument for data collection a questionnaire was used to provide sociodemographic data, information about mother’s health during pregnancy, delivery in baby-friendly hospital and breastfeeding duration. The results of logistic regression analysis showed that delivery in baby-friendly hospital had a significant association with breastfeeding duration of 6 months and more (p=0.023). Maternal age (p=0.873), marital status (p=0.628), maternal education level (p=0.228), maternal employment (p=0.949), self-perceived financial status (p=0.189), maternal health during pregnancy (p=0.874) were not significantly associated with breastfeeding duration of 6 months and more. These results support the importance of the hospital environment and health provider practices in breastfeeding promotion.

Polo-Like-Kinase (PLK) 1 activity is associated with maintaining the functional and physical properties of the centrosome's pericentriolar matrix (PCM). In this study, we use a multimodal approach of human cells (HeLa) and zebrafish embryos in parallel to phylogenic analysis to test the role of a PLK1 binding protein, cenexin, in regulating the PCM. Our studies identify that cenexin is required for tempering microtubule nucleation and that a conserved C-terminal PLK1 binding site between humans, zebrafish, and out to cnidaria is required for PCM maintenance through PLK1-dependent substrate phosphorylation events. PCM architecture in cenexin-depleted zebrafish embryos was rescued with wild-type human cenexin, but not with a C-terminal cenexin mutant (S796A) deficient in PLK1 binding. We propose a model where cenexin's C-terminus acts in a conserved manner in eukaryotes, excluding nematodes and arthropods, to anchor PLK1 moderating its potential to phosphorylate PCM substrates required for PCM maintenance and function.