REFERENCES TO THE PREVIOUS POST

BLOGGING ASSIGNMENT 3 – LONG DISTANCE SIGNALING.

Endocrine cells are responsible for long distance communicating with cells in the body. The signal molecules secreted are called hormones which are carried in the bloodstream to the target cells. Putative cell signals are also involved in cell communications that include chemotactic agents and neuronal impulses.

Muscle cells contain some level of intelligence where communication is known as “interactive regulation” since intrinsic and extrinsic mechanisms are involved.  According to Medical College of Georgia, scientist have shown that there is protein known as LRP4 that is found in muscle cells that is responsible for communication. It receives signals from the signaling cell that it is time to start the formation of receptors that will facilitate the communication process between 2 cells.

For example, the follicle stimulating hormone, secreted by the gonadotrophs of the anterior pituitary gland, sends signals to the ovaries, to stimulate the maturation of ovarian follicles. This is considered long distance cell communication because of the use of nucleic receptors.

Therefore the end result of this type of signaling is the production of ovarian follicles in the ovaries.

An intracellular receptor is located inside of the cell which is often located on the cell nucleus. The IP3 receptor is located in the endoplasmic reticulum. In this case, hormones are able to diffuse across the cell membrane and bind with the receptor protein on the nucleus and recruits co-activators and polymerase.  After this process occurs, transcription of certain genes is influenced. 

Image

 

Figure 1: diagram illustrating how a hormone signal is received by a cell.

Source:  https://www.boundless.com/biology/cell-signaling/transcription-and-cytoplasmic-responses/responses-to-extracellular-signals/

DISEASES IN CELLS & DIFFERENT TYPES OF ENDOCRINE CELL SIGNALING.

The first type of endocrine signaling is Adrenal signaling whose function is to produce steroid hormones. The adrenal cortex is responsible for this and is located above the kidneys and is made up of three layers; Zona glomerulosa, Zona fasciculata and Zona reticularis.

Another type of signaling is Glucocorticoid signaling which deals with stress response, metabolism, immune/inflammatory response. 

In sperm-oocyte cell signaling, it is regulated by insulin-like peptides, Wnts and Hedgehogs. These signals are used to regulate cell proliferation, apoptosis and differentiation. In the model organism, C. elegans, the sperm secrete a hormone known as MSP (major sperm protein) which stimulates ovulation by influencing oocyte maturation and ovarian cell contraction. A mutation in the MSP gene can cause amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). Oocytes communicate with sperm by secreting molecules derived from polyunsaturated fatty acids which are responsible for guiding sperm  to the fertilization site.

 

 

Ribbitttt !

HI GUYS ! 

guess what i am? a CELL ! 

that’s right.. Image

the picture above is a mass of egg cells, that black dot that you see? it’s a huge mass of cells & one day they (or we) would grow into tadpoles 😀

the picture above is a picture of me 😀 exciting right?

so basically i’m responsible for existence. 🙂

the pituitary gland produces a follicle stimulating hormone which in turn then act on the ovaries which in turn stimulates sex hormone production & that’s how i come about 😮

During the mating season, a male frog calls out to a female frog. If she accepts they begin mating and the female releases her eggs while simultaneously the male frog, releases his sperm over the eggs. therefore i’m a part of fertilization!!

Image

the picture above is a picture of meee 🙂

my cell consists of the upper and lower hemisphere. the upper hemisphere is the animal pole and the lower hemisphere is the vegetal pole. the components of my cell are as follows: ribosomes (site of biological protein synthesis), nucleus (contains my genetic material), mitochondira (generates most of my ATP) and the yolk (feeds on developing embryo). 

my fate: to become a tadpole. 

 

references:

http://nationalzoo.si.edu/Animals/ReptilesAmphibians/Facts/FactSheets/Africanclawedfrog.cfm

http://www.earthrangers.com/wildwire/omg_animals/life-cycle-of-a-frog/

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/F/FrogEmbryology.html

Xenopus laevis (African clawed frog)

biol 2061 – Cell & Developmental Biology

for this new course, the model organism i decided to do is the African Clawed Frog. 

throughout this semester and for this course, we will be looking at this organism, particularly a specific cell. 

                                                               AFRICAN CLAWED FROG: 

Xenopus – strange foot 

laevis – smooth 

this greenish-greyish frog is found mainly in the Sub-Saharan Africa and in North America, South America and Europe in isolated populations. they are aquatic frogs that have the characteristic three short claws on each webbed hind foot. they have no tongue, ears or teeth and their bodies are flattened. they can grow up to a length of five inches or thirteen centimeters. 

their hind, clawed legs are used to tear apart food and its for eating and shoving food down their throats (they feed on living and dead things and organic waste). Since they are completely aquatic, they have powerful, muscular legs for swimming. 

As mentioned earlier, they have no ears, instead they have lateral lines located on the underside of their body which senses movements and vibrations in the water. 

male and female frogs are significantly different. male frogs are smaller than the female frogs by up to 20% and have slim bodies, while the females are larger and somewhat fatter since their eggs are located in their rear legs. 

this particular type of frog is a popular model system for its embryos and eggs because of its experimental tractability and its evolutionary relationship with humans which is the main reason i chose this organism.

sooo… let’s get started!

 

references: 

http://www.reptilesofaz.org/Turtle-Amphibs-Subpages/h-x-laevis.html

http://en.wikipedia.org/wiki/African_clawed_frog