Prepare for your exams
Get points
Guidelines and tips
Sell on Docsity
Docsity AI

Prepare for your exams

Study with the several resources on Docsity

Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips

Sell on Docsity

Docsity AI

Log in Sign up

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search for your university

Find the specific documents for your university's exams

Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

Earn points by helping other students or get them with a premium plan

Share documents

20 Points

For each uploaded document

Answer questions

5 Points

For each given answer (max 1 per day)

All the ways to get free points

Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

Understanding Animal Development: Cell Potency, Gene Expression, and Morphogenesis, Study notes of Chinese Language

Rutgers University - Camden Chinese Language

An in-depth exploration of the fundamental processes that shape the development of an animal, including cell potency, differential gene expression, and morphogenesis. It covers topics such as pluripotent, totipotent, and multipotent stem cells, cell determination, cell differentiation, nuclear equivalence, and morphogenesis. The document also discusses the five stages of development, including fertilization, cleavage, blastulation, gastrulation, and organogenesis.

Typology: Study notes

2010/2011

Uploaded on 07/11/2011

koofers-user-ntp-1 🇺🇸

10 documents

1 / 6

This page cannot be seen from the preview

Don't miss anything!

Animal Development: Chapter 50

The development of the form of an animal is a consequence of a balanced combination

of several fundamental processes:

Cell Potency

Pluripotent: embryonic stem cells originate as inner mass cells within blastocyst

oStem cells can become any tissue in body, excluding placenta

Totipotent: only morula’s cells are totipotent

oAble to become all tissues & placenta

Multipotent: give rise to cells from multiple, but limited number of lineages

oe.g. blood stem cells

Stem cells: not all cells differentiate

oat each level, remain in an uncommitted state; retain ability to

odifferentiate when needed

Differential Gene Expression

Determined: when cell is irreversibly committed to specific cell fate

Cell differentiation: normal process by which less specialized cell develops or matures

to possess that determined or distinct form & function (differential gene expression)

Nuclear equivalence: cell expression during both cell determination & cell

differentiation

oi.e. all cells have the same gene pool; no genetic change or loss in genetic

information

Morphogenesis – the change of form

Requires cell division & growth, as well as cell determination & cell differentiation

Requires pattern formation when cells:

oCommunicate by signaling

oPlan cell migration

oChange shape

oInteract with the ECM

oGo through apoptosis

Development

5 stages of development include:

oFertilization:

restores diploid chromosome number

determines sex of offspring

initiates development of form

oCleavage:

series of rapid cell divisions without growth phase

cell number increases by mitosis

zygote is partitioned into many small blastomeres

oBlastulation:

Formation of segmentation cavity or blastocoele within mass of cleaving

blastomeres

- 1 -

Discover Study notes of Chinese Language Rutgers University - Camden

Partial preview of the text

Download Understanding Animal Development: Cell Potency, Gene Expression, and Morphogenesis and more Study notes Chinese Language in PDF only on Docsity!

Animal Development: Chapter 50

 The development of the form of an animal is a consequence of a balanced combination of several fundamental processes: Cell Potency  Pluripotent: embryonic stem cells originate as inner mass cells within blastocyst o Stem cells can become any tissue in body, excluding placenta  Totipotent: only morula’s cells are totipotent o Able to become all tissues & placenta  Multipotent: give rise to cells from multiple, but limited number of lineages o e.g. blood stem cells  Stem cells: not all cells differentiate o at each level, remain in an uncommitted state; retain ability to o differentiate when needed Differential Gene Expression  Determined : when cell is irreversibly committed to specific cell fate  Cell differentiation: normal process by which less specialized cell develops or matures to possess that determined or distinct form & function (differential gene expression)  Nuclear equivalence: cell expression during both cell determination & cell differentiation o i.e. all cells have the same gene pool; no genetic change or loss in genetic information Morphogenesis – the change of form  Requires cell division & growth, as well as cell determination & cell differentiation  Requires pattern formation when cells: o Communicate by signaling o Plan cell migration o Change shape o Interact with the ECM o Go through apoptosis Development  5 stages of development include: o Fertilization:  restores diploid chromosome number  determines sex of offspring  initiates development of form o Cleavage:  series of rapid cell divisions without growth phase  cell number increases by mitosis  zygote is partitioned into many small blastomeres o Blastulation:  Formation of segmentation cavity or blastocoele within mass of cleaving blastomeres

 Characteristic of each species o Gastrulation:  Blastula becomes three-layered embryo ( gastrula)  Basic body plan laid down as 3 germ layers o Organogenesis:  Organs are formed (~5th^ week of gestation) Fertilization  External fertilization: o e.g. echinoderms, amphibians  PM of egg is surrounded by vitelline envelope , plus a glycoprotein jelly coat  (Echinoderms Fig 50-1)  Species-specific bindin receptors on egg vitelline envelope only recognize bindin molecules on sperm from same species  “lock & key” mechanism ensures eggs fertilized ONLY by sperm of same species (preventing interspecific fertilization) o External Prevention of Polyspermy (echinoderms)  Fast block (transient): Na+^ channels in egg PM open; membrane depolarizes; prevents additional sperm from fusing to egg PM; normal potential restored within minutes of fusion  Slow block (permanent) : release of Ca+2^ from egg ER; PM fuses with egg cortical vesicle; secrete proteases, mucopolysaccharides, & peroxidases; envelope hardens removing remaining sperm- binding proteins  Slow- Block - Cortical Reaction  Internal fertilization: o e.g. mammals  PM of egg surrounded by thick & noncellular zona pellucida , & then a layer of follicular cells – corona radiata  (Mammals)  Chemotaxis (gets attracted) of sperm by egg  Capacitation: (enzymes & proteins) in female reproductive tract; sperm maturation, increased sperm motility  Exocytosis of sperm acrosomal enzymes  Sperm penetration of corona radiata  Sperm binds egg’s zona pellucida via species-specific glycoproteins (ZP1-3) receptors  Enzymes released from cortical granules alter sperm receptors on egg’s zona pellucida; prevent further sperm penetration o Egg activation:

Fertilization Initiates the Gray Crescent During Cleavage:  e.g. frog’s egg: rearrangement of egg cytoplasm ( cortical rotation) results in establishment of dorsal/ventral axis & Gray Crescent region (area; opposite side to sperm) Blastulation: develops blastocoel  1: Morula:  2: Blasutla:  The 32-cell stage of cleavage, embryo becomes a morula which is then followed at the 64 cell stage with a blastula with central cavity (blastocoel) Gastrulation: development of three-layered embryo ( gastrula) & basic body plan is laid down as 3 germ layers: o outer ectoderm o middle mesoderm o inner endoderm  new cell-to-cell relationships are formed & internal architecture of cell changes Gastrulation in Sea Star:  vegetal pole cells in blastula flatten & invaginate to meet opposite wall obliterating blastocoel  forms archentron or primitive digestive tube; develops gut into some groups  end of archentron that opens to exterior (blastopore) becomes future anus Gastrulation in Frog:  Start of gastrulation in frog marked by pushing inward (invagination) of cells in region of embryo once occupied by middle gray of crescent invaginate and reduce the blastoceol  Archentron forms  Germ layers form: o Ectoderm: skin, brain, spinal cord, other neurons, sensory receptors o Mesoderm: notocord, muscles, blood, bone, sex organs o Endoderm: inner lining of gut, liver, pancreas; inner lining of lungs, inner lining of bladder, thyroid/parathyroid glands, thymus Gastrulation in Birds (Fig 50-10)  Hensen’s Nodes: established longitudinal axis & polarity of embryo o Similar to gray crescent in frogs o Forms notochord, mesoderm  Primitive Groove: equivalent to blastopore in echinoderms  Primitive Streak: establishes bilateral symmetry & germ layers o Some cells of epiblast migrate into anterior of embryo through primitive streak to form mesoderm while others remain & develop as ectoderms o Hypoblast – develops into the endoderm Gastrulation in Mammals : no yolk!  Radial (rotational) cleavage: leads to blastocyst with inner cell mass; forms epiblast and hypoblast and some extra-embryonic tissues

 Blastocoel – becomes filled with cells of the inner cell mass o Forms epiblast (mesoderm & ectoderm) & hypoblast (endoderm)  Outer trophoblast cells : will become the placenta & produce chorion Human Organogenesis: after gastrulation: formation of organs  Organs derived from each germ layer Process of Induction (ch17)  Induction : individual cells are being “told” what they’re supposed to become o Two cells adjacent to each other influence each other’s development through signaling pathways o Stem cells differentiate through gene expression leading to cell specialization Induction of Nervous System (Fig 50-11)  Neurulation: begins when notochord signals ectoderm germ layer above it to form thick & flat neural plate o Detaches from endoderm (below it) to form closed tube surrounded in somite (mesoderm) o Neural tube differentiates into spinal cord & brain, eventually forming CNS Heart Formation in Birds & Mammals (Fig 50-12)  Allantois (space) & yolk sac (yellow) develop from endoderm & mesoderm o Allontois – stores nitrogenous wastes in reptiles & birds, part of umbilical system in mammals o Yolk sac – contains food acts as temporary center for formation of blood cells Extra Embryonic Membranes (Fig 50-13)  Supportive extra-embryonic membrane develops from combination of 2 germ layers: o chorion (blue) & amnion (red) develop from ectoderm & mesoderm  chorion – used in gas exchange  amion – fluid-filled & acts as a shock absorber Human Development  7 days: blastocyst implants o cells of trophoblast (outer layer that eventually forms chorion) & amnion surrounding embryo proliferate & invade endometrium  10 days: trophoblast cells differentiate into chorion (produce hCG) o embryonic disk – forms the 3 germ layers: o CL releases E and P for endometrial & placental development o LH & hCG both stimulate CL to produce E and P maintaining pregnancy o Yolk sac – contains early nutrition  25 days: maternal blood vessels provide embryo with O2 & nutrients o chorion invades endometrium via villi which becomes vascularized o secretes E and P to maintain pregnancy o chronic villi will become placenta – organ of exchange between maternal & fetal circulation  provides nutrients to embryo & removes wastes derived from embryonic chronic & maternal

Understanding Animal Development: Cell Potency, Gene Expression, and Morphogenesis, Study notes of Chinese Language

Related documents

Partial preview of the text

Download Understanding Animal Development: Cell Potency, Gene Expression, and Morphogenesis and more Study notes Chinese Language in PDF only on Docsity!

Animal Development: Chapter 50