Octopus Research Articles

The CLE33 peptide represses phloem differentiation via autocrine and paracrine signaling in Arabidopsis

Plant meristems require a constant supply of photoassimilates and hormones to the dividing meristematic cells. In the growing root, such supply is delivered by protophloem sieve elements. Due to its preeminent function for the root apical meristem, protophloem is the first tissue to differentiate. This process is regulated by a genetic circuit involving in one side the positive regulators DOF transcription factors, OCTOPUS (OPS) and BREVIX RADIX (BRX), and in the other side the negative regulators CLAVATA3/EMBRYO SURROUNDING REGION RELATED (CLE) peptides and their cognate receptors BARELY ANY MERISTEM (BAM) receptor-like kinases. brx and ops mutants harbor a discontinuous protophloem that can be fully rescued by mutation in BAM3, but is only partially rescued when all three known phloem-specific CLE genes, CLE25/26/45 are simultaneously mutated. Here we identify a CLE gene closely related to CLE45, named CLE33. We show that double mutant cle33cle45 fully suppresses brx and ops protophloem phenotype. CLE33 orthologs are found in basal angiosperms, monocots, and eudicots, and the gene duplication which gave rise to CLE45 in Arabidopsis and other Brassicaceae appears to be a recent event. We thus discovered previously unidentified Arabidopsis CLE gene that is an essential player in protophloem formation.

OCTOPUS MAPPING one of the MADMAPS: NATO Octopus, control over the weapons’ sales

The first version of the NATO Octopus map was published in the Mad Maps Atlas (Lambert & Zanin, 2019, p. 116), in 2019, in French, edited by Armand Colin. The aim of this Atlas was to propose, in a...

Octopuses, like humans, sleep in two stages

Octopuses, like humans, sleep in two stages

First detection of an ocellate octopus in the Revillagigedos ecoregion, a biodiversity hotspot located in the Tropical East Pacific Province.

The biodiversity of mollusks, particularly cephalopods, has not been exhaustively determined in the Revillagigedos ecoregion, which is a biodiversity hotspot for several marine groups located in the Tropical East Pacific Province. In our study, we detected and examined ocellate octopuses from Socorro and Clarion Islands, and determined their identity using morphological criteria and molecular data from two mitochondrial genes (COIII and COI). The taxon identified was Octopus oculifer, a species considered endemic to the Galapagos Archipelago. In addition, according to our analyses, O. mimus, O. hubbsorum and O. oculifer are very closely related and may represent a species complex comprised of three morphotypes. We found that the evolutionary relationships among octopuses are not determined by the presence of ocelli. This study is the first to report a clade represented by ocellate and non-ocellate species, in addition, the identity of cephalopods in the Revillagigedos was determined with analytical support.

How octopuses taste with their arms — all eight of them

How octopuses taste with their arms — all eight of them

How octopuses taste with their tentacles

How octopuses taste with their tentacles

Now I Know the Truth about Octopuses (and the Lies We Tell Our Children)

Now I Know the Truth about Octopuses (and the Lies We Tell Our Children)

Variation in Catch Size and Changes in Reproductive Biology of Common Octopus Octopus vulgaris in the Coastal Waters Off Gyeongnam, Korea

Variation in Catch Size and Changes in Reproductive Biology of Common Octopus Octopus vulgaris in the Coastal Waters Off Gyeongnam, Korea

A Reservoir of Pluripotent Phloem Cells Safeguards the Linear Developmental Trajectory of Protophloem Sieve Elements.

Plant cells can change their identity based on positional information, a mechanism that confers developmental plasticity to plants. This ability, common to distinct multicellular organisms, is particularly relevant for plant phloem cells. Protophloem sieve elements (PSEs), one type of phloem conductive cells, act as the main organizers of the phloem pole, which comprises four distinct cell files organized in a conserved pattern. Here, we report how Arabidopsis roots generate a reservoir of meristematic phloem cells competent to swap their cell identities. Although PSE misspecification induces cell identity hybridism, the activity of RECEPTOR LIKE PROTEIN KINASE 2 (RPK2) by perceiving CLE45 peptide contributes to restrict PSE identity to the PSE position. By maintaining a spatiotemporal window when PSE and PSE-adjacent cells' identities are interchangeable, CLE45 signaling endows phloem cells with the competence to re-pattern a functional phloem pole when protophloem fails to form.

Consider the Octopus

Consider the Octopus

Rosy octopuses are more warty the deeper they dwell in the sea

Rosy octopuses are more warty the deeper they dwell in the sea

A Cellular Insulator against CLE45 Peptide Signaling

Plants continuously elaborate their bodies through post-embryonic, reiterative organ formation by apical meristems [1]. Meristems harbor stem cells, which produce daughter cells that divide repeatedly before they differentiate. How transitions between stemness, proliferation, and differentiation are precisely coordinated is not well understood, but it is known that phytohormones as well as peptide signals play important roles [2-7]. For example, in Arabidopsis thaliana root meristems, developing protophloem sieve elements (PPSEs) express thesecreted CLAVATA3/EMBRYO SURROUNDING REGION-RELATED 45 (CLE45) peptide and its cognate receptor, the leucine-rich repeat receptor kinase (LRR-RK) BARELY ANY MERISTEM 3 (BAM3). Exogenous CLE45 application or transgenically increased CLE45 dosage impairs protophloem formation, suggesting autocrine inhibition of PPSE differentiation by CLE45 signaling. Since CLE45 and BAM3 are expressed throughout PPSE development, it remains unclear how this inhibition is eventually overcome. The OCTOPUS (OPS) gene is required for proper PPSE differentiation and therefore the formation of continuous protophloem strands. OPS dosage increase can mend the phenotype of other mutants that display protophloem development defects in association with CLE45-BAM3 hyperactivity [8, 9]. Here, we provide evidence that OPS protein promotes differentiation of developing PPSEs by dampening CLE45 perception. This markedly quantitative antagonism is likely mediated through direct physical interference of OPS with CLE45 signaling component interactions. Moreover, hyperactive OPS confers resistance to other CLE peptides, and ectopic OPS overexpression triggers premature differentiation throughout the root. Our results thus reveal a novel mechanism in PPSE transition toward differentiation, wherein OPS acts as an "insulator" to antagonize CLE45 signaling.

Lugar y sentido de lugar en un camino de la costa atlántica patagónica, 1950-1970

El objetivo del trabajo es analizar cómo recolectores de pulpo (pulperos) construyeron lugar, y dieron sentido de lugar a un camino de terracería en un tramo paralelo y lindero a la costa atlántica patagónica de 1950 a 1970. Se utilizó una metodología cualitativa y participativa, basada en estas técnicas etnográficas: entrevistas, entrevistas en profundidad, recorridos de campo y referenciación geográfica de los parajes reconocidos por los pulperos. Como resultado, los informantes identificaron parajes donde se establecían los pulperos, que se cartografiaron, y se les asignó topónimos reconocidos por ellos. La limitante es que no se profundizó en las trasformaciones del camino, aunque la originalidad radica en el uso de los conceptos paraje (lugar), sentido de lugar y paisaje en la reconstrucción del camino, a partir de una actividad productiva artesanal. En conclusión, los afectos que residen en la memoria de los pulperos resultaron centrales en la construcción social del camino y los parajes como lugar, en el sentido geográfico.

Octopus minds must lead to octopus ethics

Octopus minds must lead to octopus ethics

Sensory and Nutritional Characteristics of Seasoned Laver Pyropia yezoensis with Concentrates of Octopus Octopus vulgaris Cooking Effluent

Sensory and Nutritional Characteristics of Seasoned Laver Pyropia yezoensis with Concentrates of Octopus Octopus vulgaris Cooking Effluent

What is in an octopus's mind?

What is in an octopus's mind?

Octopus experience

Octopus experience

The perfecting of the octopus

The perfecting of the octopus

What and where is an octopus’s mind?

What and where is an octopus’s mind?

The octopus mind and the argument against farming it

The octopus mind and the argument against farming it