U.S. Department of Health and Human Services
​​

Laboratory of Cellular and Developmental Biology

Jurrien Dean, M.D., Chief

​Research Images

Images or videos appear below. Clicking images or videos provides an expanded view.

TitleDescriptionImage
The WAFFL in Action

This video features a 96-well system called the Whole Animal Feeding Flat (WAFFL). The WAFFL was designed by the Developmental Genomics Section in the Laboratory of Cellular and Developmental Biology, and enables the housing and feeding of flies while reducing the number of required manipulations. The WAFFL system is comprised of four main units: (1) Food Reservoir, (2) Feeder (housing), (3) Receiver and (4) Transfer Adapter. The WAFFL offers several advantages such as minimal fly handling, less food and drug required per treatment, the ability to test 1-2 flies per well, the ability to provide multiple treatments per unit (e.g. different drugs or different concentrations) and compatibility with standard laboratory equipment and automation robots. This video shows a researcher easily placing flies in the WAFFL, treating flies, making changes between treatments, transferring flies, and harvesting flies after treatment.

Lab members 2017

(Left to right) Guoyou Liu, Luis Diaz, Xiang Guo, Ben Leadem, Maria Soledad Ivaldi, Ivan Krivega, Dr. Dean, Jun Zhang

(Left to right) Guoyou Liu, Luis Diaz, Xiang Guo, Ben Leadem, Maria Soledad Ivaldi, Ivan Krivega, Dr. Dean, Jun ZhangEnlarge
A working model of the relationship between chromatin looping and transcription activation in the β-globin locus

In erythroid cells, the β-globin LCR and gene are occupied by the Ldb1/LMO2/TAL1/GATA-1 complex, and Ldb1 dimerization is the basis of loop formation (Song, et al., Molecular Cell, 2007; Deng et al., Cell, 2012). The locus moves from the nuclear periphery to the interior for robust transcription of the gene in transcription factories (Song et al., Blood, 2010). (A) Looping could be promoted by pol II density and by transcription in a factory. (B) Alternatively, looping might be facilitated by a cell-type specific chromosomal organization that is stabilized by Ldb1 dimerization (reviewed in Krivega and Dean, Current Opinion in Genetics & Development, 2012). Mutational analysis of Ldb1 favors the latter model (I. Krivega and A. Dean, Genes and Development, 2014).

A working model of the relationship between chromatin looping and transcription activation in the β-globin locusEnlarge
3D View of WAFFL Feeder Plate Design

This animation shows a 360 degree view of the Whole Animal Feeding Flat (WAFFL) Feeder Plate, a unit within the WAFFL system. The animation shows details of the Feeder Plate including its bottom openings, inside wells, and outside structure. The WAFFL system was designed by the Developmental Genomics Section in the Laboratory of Cellular and Developmental Biology.

Photo showing polytene chromosomes of Drosophila salivary glandsHighly replicated polytene chromosomes of the Drosophila salivary glands stained with DAPI (blue) and antibodies directed against gypsy insulator proteins Su(Hw) (green) and Mod(mdg4)2.2 (red).Photo showing polytene chromosomes of Drosophila salivary glandsEnlarge
Photo showing epifluorescent whole-mount staining of third instar larval imaginal discEpifluorescent whole-mount staining of third instar larval imaginal disc to visualize insulator bodies using anti-CP190 antibodies (green) and DAPI (blue).Photo showing epifluorescent whole-mount staining of third instar larval imaginal discEnlarge
Mouse FertilizationFertilization occurs in the ampulla of the oviduct where the fertilizing sperm encounters an ovulated egg. After initial binding to the zona pellucida, the sperm penetrates through the zona matrix to fuse with the egg plasma membrane. The subsequent cortical granule reaction leads to a potent block to polyspermy.Mouse FertilizationEnlarge
Early Mouse DevelopmentMaternal RNA and proteins accumulate during oocyte growth. The zona pellucida that surrounds ovulated eggs (green) is modified following fertilization (red) to prevent polyspermy. Activation of the embryonic genome occurs in the 2-cell embryo and, following the third cell division, embryos compact to form morulae and then blastocysts that implant on the wall of the uterus.Early Mouse DevelopmentEnlarge