INTRODUCTION

                                            Pavel Krejci

                                       DEVELOPMENTAL BIOLOGY

- central to all other areas of biology – unites cell biology, genetics and morphology

- in last 25 years grew into the most exciting and dynamic field of biology…..due to the advances in
three main traditions: the experimental embryology, developmental genetics and molecular biology.
All animals develop similarly, that including the worm, fly, fish or mammal.

- significant impact on society, in vitro fertilization, teratology, birth defects.

- future impact: functional genomics and functional proteomics, disease therapy, prenatal screening,
transplantation, embryonal stem cells, therapeutic cloning.





                                   COMMON FEATURES OF DEVELOPMENT



Developmental Biology: A science that explains how a structure of organism changes with time

- structure or morphology or anatomy: an arrangement of parts (large/small, organs, parts of an
organ, cells in a part of an organ)



- many forms of development: embryonic (zygote          complete organism), postembryonic
(larva         adult organism), regeneration (asexual reproduction through budding, replacement of
lost parts)



-….but same problems

1. Regional specification: pattern appearance in uniform mass of cells.



2. Cell differentiation: 200 different cell types in vertebrate body, each differ by particular
proteins made through activation of particular genes.



3. Morphogenesis: cell and tissue movements creating the 3D design of organ.



4. Growth: increase in size and control of proportions among the parts.

                              GENOMIC EQUIVALENCE, CLONING OF ANIMALS



                                           GAMETOGENESIS



- male and female gametes

- fertilized egg or ovum

- each gamete is 1n – a haploid set of chromosomes

- Zygote is 2n – a diploid set of chromosomes



Gametes are formed from germ cells in the embryo

Germ line: cells that can or will become the future gametes.

Somatic cells: all other except the germ line.

Future germ cells decide to be „germ“ early in the embryo development somethimes through inheriting
a cytoplasmic element from the egg – a germ plasm (polar granules in C. elegans).

During embryonic development germ cells multiplicate and migrate to find a gonad.

Gonad: mesodermal by origin and composed entirely of somatic cells, when germ cells arrrive they
integrate into gonad and in post-embryonal life undergo GAMETOGENESIS