developmental exam 2!

Differentiation

The process producing overt change in appearance or biochemistry in cells.

Specification

The labile stage of cellular fate determination, where the cell can still change in a neutral environment.

Determination

The stage where cells will differentiate autonomously, and their fate is set and irreversible.

Mosaic Developmental Pattern

A developmental pattern predominantly seen in invertebrates where cells from early embryos differentiate to their normal fate when isolated.

Autonomous Specification

A specification type where cells are predetermined and differentiate based on internal signals regardless of environment.

Syncytial Specification

Specification involving one cell with multiple nuclei due to incomplete cell division.

Conditional Specification

Specification where cells have a flexible fate and can form complete embryos when isolated.

Induction

The process of one cell type influencing or changing the behavior of another nearby cell.

Competence

The ability of a responding cell to respond to inductive signals.

Paracrine Signaling

Local signaling that involves factors affecting adjacent cells.

Juxtacrine Signaling

Signaling that requires cells to be in close contact to interact.

Cadherins

Calcium-dependent adhesion molecules that mediate cell-cell adhesion.

E-cadherin

A transmembrane protein crucial for cell-cell adhesion in epithelial tissues.

P-cadherin

An adhesion molecule that binds to other P-cadherin molecules on neighboring cells.

Integrins

A class of surface adhesion proteins critical for development, functioning as dimers.

Morphogenesis

The biological process that causes an organism to develop its shape.

Fate Mapping

A technique used to trace the contribution of specific cells to different structures during development.

Epithelial-Mesenchymal Transition (EMT)

A process where epithelial cells lose their cell polarity and cell-cell adhesion, gaining migratory and invasive properties.

Fibronectin

A glycoprotein of the extracellular matrix that helps in cell adhesion and migration.

Extracellular Matrix (ECM)

A complex network of proteins and carbohydrates that provide structural and biochemical support to surrounding cells.

Zygote

The fertilized egg that results from the fusion of sperm and egg.

Gastrulation

A phase in embryonic development where the blastula reorganizes into a multilayered structure.

Blastocyst

A structure formed in the early development of mammals, consisting of an inner cell mass and an outer trophoblast.

Acrosomal Vesicle

A structure in sperm that contains enzymes necessary for penetrating the egg's outer layer.

Polyspermy

The condition where an egg is fertilized by more than one sperm, leading to triploidy.

Sonic Hedgehog Gene (Shh)

A gene that plays crucial roles in embryonic development, including in eye formation.

Endocrine Disruptors

Chemicals that can interfere with endocrine (hormonal) systems.

Ingression

The process where cells move individually from a sheet into the interior of the embryo.

Blastomere

An early embryonic cell formed by the division of a zygote.

Morphogens

Signaling molecules that cause cells to change their fate in a concentration-dependent manner.

Regulative Development

Development where cells can adjust their fates based on interactions with neighboring cells.

Cell Adhesion Molecules (CAMs)

Proteins located on the cell surface involved in binding with other cells or with the extracellular matrix.

Trophectoderm

The outer layer of cells in the blastocyst that contributes to placental formation.

Inner Cell Mass (ICM)

The cluster of cells in the blastocyst that will develop into the embryo.

Epidermal Growth Factor (EGF)

A growth factor that stimulates cell growth, proliferation, and differentiation.

Ectoderm

The outermost layer of cells in the embryo that develops into the skin and nervous system.

Mesoderm

The middle layer of cells in the embryo that develops into muscle, bone, and other systems.

Endoderm

The innermost cell layer that forms the digestive tract and associated organs.

Fetal Growth

The period of development from 9 weeks post fertilization until birth.

External Fertilization

A process where fertilization occurs outside the female body, as in many aquatic animals.

Internal Fertilization

A process where fertilization occurs inside the female body, typical of many terrestrial animals.

IVF (In Vitro Fertilization)

A fertility treatment where eggs are combined with sperm outside the body.

Spermatogenesis

The process of sperm cell development.

Zygote's Nuclear Remodelling

The process where the nuclear membrane of the zygote breaks down and is remodeled after fertilization.

Occlusion of Fertilization Cues

Prevention of polyspermy to ensure only one sperm fertilizes the egg.

Zona Pellucida

A glycoprotein layer surrounding the egg that plays a crucial role in fertilization.

L-selectins

Cell adhesion molecules that help sperm and egg interact during fertilization.

Mitochondrial Function in Sperm

Mitochondria provide ATP necessary for sperm motility.

Cortical Granules

Enzymes in the ovum that prevent polyspermy after fertilization.

Calcium's Role in Cell Adhesion

Calcium ions are crucial for the binding of cellular adhesion molecules (CAMs).

RGD Sequence

An amino acid sequence that integrins bind to.

Hormonal Imbalances

Disruptions in normal hormonal levels that can affect fertility.

Eye Formation in Xenopus

A process where the optic vesicle induces the overlying ectoderm to form the lens.

Mutagenicity in Protein Levels

Mutations in specific proteins that can disrupt inductive interactions during development.

Two-Tailed Phenotype in Development

A phenotype resulting from the absence of the Bicoid protein, leading to the development of two tails.

Cell Sorting Mechanisms

Processes by which similar cell types adhere to each other during development.

Blastopore Lip

A critical area in the embryo that participates in organizing the body axis during development.

Chordin and Noggin

Morphogens secreted from the dorsal blastopore lip that induce dorsal fate.

Epidermal and Mesenchymal Interactions

Interactions between epithelial and mesenchymal cells that are common in embryonic development.

Transplantation Experiment

A study method used to understand cellular commitments and interactions during development.

Actin and Myosin

Housekeeping genes that are essential for muscle contraction and cell movement.

Research Techniques in Developmental Biology

Methods include finding, losing, and moving components to study cellular commitments.

Gradient Distribution of Morphogens

The concentration gradient of signaling molecules that determines the fate of surrounding cells.

Nanos and Bicoid Gradients

Morphogen gradients in insects that establish body axes.

Experimental Design in Developmental Biology

Can include techniques such as isolation, reaggregation, and transplantation to study cell fate.

Cellular Communication Types

Include juxtacrine and paracrine signaling mechanisms that affect cell interactions.

Epithelial Tissue Characteristics

Consists of layers of tightly packed cells and plays a key role in protection and absorption.

Mesenchymal Tissue Characteristics

Composed of loosely packed cells and involved in structural support and development.

Cell Migration Patterns

The movement of cells during development influenced by extracellular matrix properties.

Embryonic Axis Organization

The spatial orientation of developmental structures in embryos determined by signaling pathways.

Sonic Hedgehog Protein Function

A signaling molecule that plays crucial roles in cell communication during embryonic development.

Dorsal-Ventral Axis Specification

The differentiation of the embryo into dorsal (back) and ventral (belly) regions.