Sentences with word «ovule»

For instance, in the case of humans, the early stages of ovule formation occur before women are born, while they are still in their mother's womb.

At the start of reproductive life an ovary contains, on average, several thousands of immature ovules in a resting state that can last for several decades.

«Through examination of Arabidopsis ovules by highly sensitive live - imaging, we were able to see that successful fertilization of the two female gametes triggers an unprecedented cell fusion between the persistent synergid cell and the endosperm (SE fusion), which eventually leads to inactivation of the persistent synergid cell.»

In a study published in the latest issue of Nature Communications, researchers at Instituto Gulbenkian de Ciencia (IGC; Portugal), at University of Algarve (Portugal), and at University at Albany (USA) discovered in the fruit fly a molecular «alarm clock» that tells resting ovules when is the right time to wake up.

The mature ovule in most flowering plants, including Arabidopsis thaliana, contains a seven - celled embryo sac consisting of two synergid cells, one egg cell, one central cell and three antipodal cells.

And oocytes are even worse because ovules are formed in early stages of development and working with embryos is technically complex.»

An unexpected property of this new molecular alarm clock is that it is set at early stages of ovule formation, long before the cell needs to be awakened.

It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth with in the motherplant.

Gymnosperms (Gymnospermae) are a group of seed - bearing plants with ovules borne on the edge or blade of an open sporophyll, the sporophylls usually arranged in cone - like structures.

The other major group of seed - bearing plants, the Angiosperms, have ovules enclosed in a carpel, a sporophyll with fused margins.

What is exceptional is that the male cones possess a few sterile ovules and nectar, which indicates a failed attempt to invent the bisexual flower.

During their resting period, ovules turn off their genes to enter an almost hibernation - like state.

But how does each resting ovule know that it is time to prepare for ovulation?

Paulo Navarro - Costa, first co-author of this study and researcher at the IGC explains: «Similarly to humans, fruit fly ovules also have a resting period during meiosis — the specialized cell division required for the formation of healthy reproductive cells.

Rui Martinho clarifies the mechanism: «When ovules begin to form, a protein called dKDM5 modifies the chromosomes in a way that they can only activate their genes at the right time.

Legend: a = anther, p = petal, s = sepal, pi = pistil, ovl = ovule - like structures.

Transmission electron microscopy of the unfertilized ovule revealed a very thin cell wall between the synergid cell and central cell wall, which was assumed to be necessary for rapid disintegration of the cell walls.

«Identification of new protein essential for ovule, sperm formation.»

For maximum benefits, HMF Candigen Cream should be used along with HMF Candigen vaginal ovules.

Reproduction of flowering plants occurs within a plant's ovule by the fertilisation of both the egg and a larger central cell by two sperm cells.

A chile seed (like any other seed) is the mature ovule of a plant.

«A molecular alarm clock awakens resting ovules.»

CRG and Eugin sign a collaboration agreement on molecular research applied to assisted reproduction (14/03/2018) The project entails creation of four working groups (Vernos, Boke, Payer, Gabaldón) that will focus their research on gaining insights into the aging of ovules, their sensitivity to the passage of time, and studying whether changes in vaginal microbiota have an impact on assisted reproduction

This additional dose of ribosomes was passed on in the cells of pollen and ovules to subsequent generations through the non-nuclear part of the cell.

The formation of the seed completes the process of reproduction in plants (started with the development of flowers and pollination), with the embryo developed from the zygote and the seed coat from the integuments of the ovule.

Sperm and ovule (stock illustration).

In comparison with gymnosperms, which possess rather rudimentary male and female cones (like the pine cone), flowering plants present several innovations: the flower contains the male organs (stamens) and the female organs (pistil), surrounded by petals and sepals, while the ovules, instead of being naked, are protected within the pistil.

The lion's share of the book is allocated to the intensively studied area of reproduction, including induction of the inflorescence and flowers, development of these structures, formation of pollen and ovules, pollination, and subsequent development of the embryo and seeds.

The carpel protects the ovules, as the fruit later protects the seed.

The longitudinally sliced carpel in the middle reveals the ovules inside, which will develop into seeds.

«These results illustrate just how important for female fertility is the early life of the ovule.

If this alarm clock is incorrectly set, for example due to defects in the dKDM5 protein, females become infertile because their ovules fail to complete meiosis.»

The results of the research team revealed the ovules keep track of time during meiosis using a process similar to a molecular «alarm clock.»

The research team led by Rui Martinho, from the Center for Biomedical Research at University of Algarve and from Instituto Gulbenkian de Ciencia, and Prashanth Rangan, from University at Albany, discovered that the timing of turning the genes back on is programmed directly into the chromosomes of the ovule.

As the ovary turns into fruit, different ovary parts become different fruit parts; when fertilized, small structures called ovules become the fruit's seeds — and more fertilized ovules means more seeds!

Therefore, this organism could help us understanding exactly how the ovule is able to turn back on its genes at the right time, a biological mystery until now.»

Plants in the genus open little five - petaled flowers and readily form classic seeds that mix genes from pollen and ovule.

Sperm cells are carried into the ovule by a pollen tube and discharged into one of two «synergid» cells located next to the egg cell.

In the case of a successful fertilisation, the second synergid cell — also known as the persistent synergid cell — is inactivated to avoid multiple pollen tubes entering the ovule.

With the exception of the sperm or ovules, our cells contain two sets of chromosomes, one from each parent.

Earlier research found that the role of synergid cells is to attract or prevent pollen tubes from reaching a plant's ovule.

A suite of signaling peptides and their receptors regulate tissue stability as the pollen tube navigates toward the ovule.

Without a proper «pollen pathway» to reach them, the plant's ovules are left barren.

The pair of synergid cells are located adjacent to the egg cell and Higashiyama's group have reported in 2001 that the synergid cells are necessary for attracting the pollen tube towards the ovule.

The pollen tube enters the ovule through an opening called the micropyle.

As a result, additional pollen tubes no longer approach the fertilized ovary, a mechanism termed as «polytubey block» (polytubey = a condition where an ovule receives multiple pollen tubes).

In a new study reported in Cell, an international group of plant biologists at ITbM, Nagoya University and other research institutes, have examined the ovules of plant cells by live - imaging to reveal a novel cell - elimination system based on an unusual cell fusion.

Published in Nature Communications, a study by scientists at the Institute for Research in Biomedicine (IRB Barcelona) headed by ICREA researcher Angel R. Nebreda has reported that the protein RingoA is a key regulator of meiosis — the cell division process that gives rise to ovules and sperm for sexual reproduction in mammals.

Torenia fournieri is unique in that the egg apparatus, containing the egg cell and the two synergid cells, protrudes from the ovule.