Bio 625, Developmental Genetics
Vicki Bautch (bautch@med.unc.edu; 6-6797)
Mark Peifer (peifer@unc.edu;
2-2271)
Week 0 Organization Meeting – Vicki Bautch and Mark Peifer
Aug. 27, 4 PM 512 Fordham Hall. Overview of Course; Requirements; Pick day/time for weekly class meeting
Week 1 (8/31) Nathan Harris
This paper reveals a new role for a pathway previously
associated with growth control.
Here they show that cell polarity is influenced by Hippo signaling. Since loss of cell polarity is a
feature of invasive tumors, Hippo may influence tumor invasion.
Week 2 (9/7) Kim Peters
Week 3 (9/14) Jean Davidson
This paper provides the first molecular pathway for
regeneration of a whole structure – the head of the freshwater polyp
Hydra. Apoptotic cells release
Wnt3, which is necessary and sufficient for head regeneration, even when
expressed in non-head regions.
Hydra are the classic species for regeneration studies, and this work
has implications for regeneration of mammalian organs and limbs.
Week 4 (9/21) Erin Kaltenbrun
Alvarado
AS. (2009). A cellular view of regeneration. Nature 460, 39-40 [News and Views].
This paper also addresses an important question in
regeneration: as a complex structure such as a limb regenerates how do the
cells know where to position themselves so that bone is inside and skin is
outside? Surprisingly, this work
shows that the edge of the amputed limb does not completely de-differentiate,
but rather forms distinct pools of progenitor cells that in some cases retain
their positional identity within the limb. Axolotls are salamanders, and they and other salamanders can
fully reconstitute functional limbs after injury.
Week 5 (9/28) David Wiley
Little
SC, Mullins MC. (2009). Bone morphogenetic protein heterodimers assemble heteromeric
type I receptor complexes to pattern the dorsoventral axis. Nat Cell Biol
11, 637-643. [plus Supplemental Figures and Information].
This paper investigates the players involved in an
important signaling pathway that affects embryonic patterning, the BMP
pathway. They show that one aspect
of patterning, dorsoventral (back-belly), requires a ligand that is a mixture
of two types of BMPs in the zebrafish.
This suggests how BMP signaling can occur in the presence of antagonists
that are also expressed, and helps in better understanding the regulation of
this pathway.
Week 6 (10/5) Tangi Smallwood
This paper describes a mechanism whereby cells adopt
either a melanophore fate or the fate of other colored chromophores in the
zebrafish. They show that foxd3
represses melpanophore fate and is a negative regulator of a locus that can be
oncogenic in humans, Mitf. They
suggest that this pathway might be relevant to human melanoma.
Week 7 (10/12) Stephanie Notowarski
This paper describes a signal, Wnt, that is necessary and
sufficient for tooth formation from the jaw. Surprisingly, the signal is produced by a small number of cells
that then "organize" the surrounding tissues to form the tooth layers
and support structures. These
findings suggest that we may be able to ÒregenerateÓ replacement teeth in
the future! (STARTING THE HALLOWEEN THEME OF "STRANGE BUT TRUE"!)
(10/19) NO CLASS - FALL BREAK
Week 8 (10/26) Soren Johnson
This paper utilizes a technique called "parabiosis"
whereby two mice are joined so that they share their circulatory system! This work shows that stem and progenitor
populations in several organs that decline with age can be"rejuvenated"
by exposure to circulation from a younger mouse. This work indicates that age-dependent
circulating factors contribute to maintenance stem and progenitor pools. (CONTINUING
THE HALLOWEEN THEME OF "STRANGE BUT TRUE"!)
Week 9 (11/2) Amanda Wisz
Week 10 (11/9) Deirdre Tatomer
This paper investigates the interesting question of how
gametes are determined as male or female in the worm C. elegans. C. elegans is a hermaphrodite, and
gamete production begins with sperm that transitions to oogenesis (eggs). Here they show that this shift is
associated with the selective association of GLD-2, part of a poly(A)
polymerase complex, with distinct binding partners. The significance is that the model of combinatorial control
of developmental processes shown here is widely used, and GLD-2 is implicated
in memory control in mammals.
(11/23) NO
CLASS THANKSGIVING
Week 11 (11/16) Minna Roh
This paper describes how symmetry is ÒbrokenÓ in the early
C. elegans embryo, to set up the two different daughter cells that will result
from the first cell division. The
sperm entry point has destabilized actomyosin contractile network that
initiates flows that act to localize polarity proteins on one side or the other
of the single cell embryo prior to mitosis. This work has implications for how asymmetric cell divisions
are regulated to maintain stem cell compartments while also producing daughter
cells that go on to differentiate, and how this process may be mis-regulated in
disease.
Week 12 (11/30) Luciana Leopold
Week 13 (12/7) FINAL EXAM