Developmental biology part 5, developmental biology of drosophila
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During oogenesis, cytoplasmic bridges called "ring canals" connect the forming oocyte to nurse cells. Nutrients and developmental control molecules move from the nurse cells into the oocyte. In the figure to the left, the forming oocyte can be seen to be covered by follicular support cells.
After fertilization of the oocyte the early embryo (or syncytial embryo) undergoes rapid DNA replication and 13 nuclear divisions until approximately 5000 to 6000 nuclei accumulate in the unseparated cytoplasm of the embryo. By the end of the 8th division most nuclei have migrated to the surface, surrounding the yolk sac (leaving behind only a few nuclei, which will become the yolk nuclei). After the 10th division the pole cells form at the posterior end of the embryo, segregating the germ line from the syncytium. Finally, after the 13th division cell membranes slowly invaginate, dividing the syncytium into individual somatic cells. Once this process is completed gastrulation starts.[23]
Nuclear division in the early Drosophila embryo happens so quickly there are no proper checkpoints so mistakes may be made in division of the DNA. To get around this problem, the nuclei that have made a mistake detach from their centrosomes and fall into the centre of the embryo (yolk sac), which will not form part of the fly.
The gene network (transcriptional and protein interactions) governing the early development of the fruit fly embryo is one of the best understood gene networks to date, especially the patterning along the antero-posterior (AP) and dorso-ventral (DV) axes (See under morphogenesis).[23]
The embryo undergoes well-characterized morphogenetic movements during gastrulation and early development, including germ-band extension, formation of several furrows, ventral invagination of the mesoderm, posterior and anterior invagination of endoderm (gut), as well as extensive body segmentation until finally hatching from the surrounding cuticle into a 1st-instar larva.
During larval development, tissues known as imaginal discs grow inside the larva. Imaginal discs develop to form most structures of the adult body, such as the head, legs, wings, thorax and genitalia. Cells of the imaginal disks are set aside during embryogenesis and continue to grow and divide during the larval stages-unlike most other cells of the larva, which have differentiated to perform specialized functions and grow without further cell division. At metamorphosis, the larva forms a pupa, inside which the larval tissues are reabsorbed and the imaginal tissues undergo extensive morphogenetic movements to form adult structures. Source of the article published in description is Wikipedia. I am sharing their material. Copyright by original content developers of Wikipedia.
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I literally found a gem however the vedio quality is this 9years old gem save me
Glad it helped
Understood in first time ..... While this topic was so confusing during my college classes........ U r a legend sir... thanks a lot...😊
All hail our lord and savior Shomu who in our time of great need saw in his omniscience to create these youtube videos to save us from failure or worse. We should reply in kind his blessings by subscribing and liking his
videos.
atharva sawant You always put same comment ??!!
But you're right..He's our Lord !! Amen _/|\_
Bicoid and Nanos are transcribed inside the nurse cells in a egg chamber during oogenesis and both the mRNAs are transported via ring canals in the egg chamber and deposited in the anterior and posterior poles of the oocyte respectively. They are not expressed in the oocyte/egg until fertilization.
Your explanation in this video from 20.00 onwards is incorrect. Please take care.
You should explain what parasegments and segments are.
Thank you Shomu Bhai. You have saved many of us!
You're welcome
Thank you so much Shomu Sir for this wonderful yet simple video that helps us understand some of the most complicated concept.
Thanks a ton Shomu sir... Your Explanation method is great... Your videos help me so much... Thank you....👍
Thank you so much sir you are really our life saviour
You're welcome
I would call the polarity from head-tail, rather than abdomen since the axis is called the anterio(head)-posterior(tail) axis
This is a laudable attempt to explain the process. But some facts are just wrong. Nanos is not a transcription factor. It is an RNA binding protein. I don't follow this channel, but it is critical to get facts right. Any newbies, please just google terms used here to verify what is being described.
Thank you sir ur way of explanation is amazing sir
I had watched many vedios of different topic explained by u
Again thank you sir
Sir I love your teaching method it was helped in Msc classes
Glad to hear that you are getting benefit from the videos
Polarity could be defined in simple terms as establishment of asymmetry, maybe in a cell or organ or even in a whole organism.
I'm going to have an exam tomorrow and this clarify a lot. Thank a lot ^^
Thank u shomu ur videos r great ...and ur method of explaining topics is great
the nurse cells surrounds the oocyte in the egg chamber... not as you explained :the nurse cells are produced inside the egg......
damn boi, you really stepped up your channel. Good job!! Wishing you the best brotha
Thank you. Glad you liked my lectures
Superb explanation..😍..thank uu sir..
You're welcome
Thank you so much for your video, it helps solving my problem towards the development of dropsophila
Thankyou so much for ur videos . U being saviour
Glad to hear that you are getting benefit from the videos
Thnxx for making these video its really so helpful for me
Amazing video, keep up your work !
Thank you so much for appreciating my efforts
Great video as always! Thank you
Thank you very much, sir
You're welcome
thank u sir......................well explained..............
Thank you...Keep it up...Best of Luck. ..
Nicely explained sir👍🏻
Thank you so much for appreciating my efforts
Thank you Sir.
You're welcome
your videos are great
More details required for this video 👍
Thank Youuu Sir ❤❤❤❤❤
You're welcome
SIŔ How could be nurse cells inside the egg cell??egg cell surrounded by 15 nurse cells mrna which codes for bicoid and nano are came from nursecells into egg cells
What about the role of Hunchback and Constans genes in anterior posterior polarity determination? Also what about the dorso-ventral polarization that is done by the dorsal and gurken?
+archishman pradhan answers to these questions are in my video on drosophila development biology lecture.
Okay, thank you :)
thankyou sir
You're welcome
thank u so much suman sir
You have drawn the larva of Drosophila incorrectly. What about pupal stage?
Thank you buddy, excelent expo
what are u trying to say brother ?
how nurse cells can be inside egg ?
it is mRNA from the follicles or nurse cells of mother which get deposited in the egg.
Yaaa nurse cells are not inside the egg cell egg cell surrounded by nurse cells
Mrna from nurse cells are deposited in the egg ok friend
Thank u so much Suman sir
You're welcome
Very useful Thank you
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thanku....shomu sir👌
It is not maternal control genes, rather maternal effect genes.
the reproductive fate of metafemale drosophila,,,can I write it's offsprings are sterile?
thank you so much !!
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Nice lecture
thanx alottttt
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Thank you sir😊
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thank u so much
+PRAMODINI PATTANAIK you're welcome
sir why is it so that the products of the genes bicoid and nanos in drosophila oocytes are stored in the form of mRNA , not as protein molecule though RNA in general is less stable than protein??
Vipul Chauhan So that energy is not wasted in case the oocyte does not get fertilized
hey Robyn Smith , thank you for the reply..i was waiting so long for the reply 😊😊
You're welcome
I love your wideos
+Jo Do you're welcome
Please do not use the word fragmentation of the Drosophila body. It is called segmentation of the body.
thank you 😊
Plz explain the role of Frazzled gene
thank you sir
This video is not sufficient ....
Gentetic regulation of early embryonic development drosophila ??me ye hi aayega kya
No. Other concepts are there too
love u dude i your video's
+Amrit Ghosh thank you. Glad it helped
dpp, sog, twist?
🙏🙏🙏🙏
Thank you
Sir which book is good for developmental biology I am preparing for degree lecturer please reply sir thank you sir
Scott F. Gilbert is best book for it but it's in quite detail . u can choose required topics or chapters from this book
Great sir thank u....
You're welcome
thnku sir
Thankyou sir, can you explain it in bengali
Not many people can understand
Sir Hindi language me btaye n
you could go faster and cover much more material
Thank you so much sir🙏
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Thank you so much sir 🙏
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Thank you so much sir
You're welcome