''Entomophthora'' is a fungal

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

in the family

Entomophthoraceae Entomophthoraceae is a family of fungi in the order Entomophthorales. This has been supported by molecular phylogenetic analysis (Gryganskyi et al. 2012).Gryganskyi AP, Humber RA, Smith ME et al (2012) Molecular phylogeny of the Entomophthoromyco ...

. Species in this genus are

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The ent ...

on flies and other two-winged insects. The genus was

circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle. * Circum ...

by German physician Johann Baptist Georg Wolfgang Fresenius (1808–1866) in 1856.Fresenius, G. 1856. Botanische Zeitung 14, 882-883. This fungus is parasitic and undergoes a number of stages within its life cycle, these include:

infection An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmis ...

, incubation, sporulation and mummification. Within each stage, this

pathogen In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a Germ theory of d ...

invades the host's body cells, utilising the insect's nutrients allowing it to take control over the

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

just before the host's death. Entomophthora reproduces asexually through both

budding Budding or blastogenesis is a type of asexual reproduction in which a new organism develops from an outgrowth or bud due to cell division at one particular site. For example, the small bulb-like projection coming out from the yeast cell is kno ...

and

spore In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...

s. When in the host's body, the pathogen utilises budding as a form of growth. This is done through a

fungus A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

cell developing a bud (daughter cell) on the parent cell. The parent cell then replicates its

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

and provides the daughter cell with this DNA. The daughter cell is then able to detach itself from the parent cell resulting in multiplication of the fungus. Spores are another mechanism that is utilised as a method of reproduction; the spores act like seeds in that they will flourish when environmental conditions are appropriate and begin to grow

hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one o ...

e – root like filaments. These hyphae then develop into the body of the fungus where the spores can be created once again and released into the environment to ensure further

reproduction Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. There are two forms of reproduction: Asexual reproduction, asexual and Sexual ...

occurs again. Similarly, spores are utilised as a method of transmission of this parasitic

disease A disease is a particular abnormal condition that adversely affects the structure or function (biology), function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical condi ...

, when spores come in contact with the insect either through consumption or direct contact, the pathogen is able to infect the

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

resulting in the beginning on the life cycle. The insect however has immune responses that fight against these parasites in order to defend themselves from infection.

Hemocytes A blood cell (also called a hematopoietic cell, hemocyte, or hematocyte) is a cell produced through hematopoiesis and found mainly in the blood. Major types of blood cells include red blood cells (erythrocytes), white blood cells (leukocytes), ...

are the cells within the

immune In biology, immunity is the state of being insusceptible or resistant to a noxious agent or process, especially a pathogen or infectious disease. Immunity may occur naturally or be produced by prior exposure or immunization. Innate and adaptive ...

response that are able to detect the entry of a pathogen and initiate the immune response to kill the foreign particles within the insect.

Physical characteristics

Description

''Entomophthora'' is a type of

fungal A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as one of the tradit ...

pathogen that is parasitic towards flies and other two-winged insects. When entered into a host's body, the fungal pathogen begins to invade the body cells and take control of the hosts, which in turn results in death. This relationship between a host and an organism is called parasitism. the parasite lives off or within another

organism An organism is any life, living thing that functions as an individual. Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have be ...

, in this case the

fly Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced ...

(host) and causes harm or even death to the host. Entomophthora outbreaks commonly occur in temperate regions often during spring and autumn.

Spore In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...

s are the cause infection of a host, this usually occurs in cool and humid conditions commonly in areas where flies rest.

Life cycle

Infection occurs when an insect comes in contact with the ''Entomophthora'' pathogen. Once the insect has been infected, the fungal disease begins its

transmission Transmission or transmit may refer to: Science and technology * Power transmission ** Electric power transmission ** Transmission (mechanical device), technology that allows controlled application of power *** Automatic transmission *** Manual tra ...

and development throughout the body, causing harm and soon death to the host. The stages this pathogen undergoes to impact the host and cause harm are referred to its

life cycle Life cycle, life-cycle, or lifecycle may refer to: Science and academia *Biological life cycle, the sequence of life stages that an organism undergoes from conception to reproduction *Life-cycle hypothesis, in economics *Erikson's stages of psy ...

. The first stage of the life cycle is infection, referring to the invasion of

micro-organisms A microorganism, or microbe, is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from antiquity, with an early attestation in Ja ...

into a

genome A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...

. These micro-organisms are foreign to the body. Within this stage, the host come in contact with a

conidia A conidium ( ; : conidia), sometimes termed an asexual chlamydospore or chlamydoconidium (: chlamydoconidia), is an asexual, non- motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also ...

– a type of reproductive spore through

touch The somatosensory system, or somatic sensory system is a subset of the sensory nervous system. The main functions of the somatosensory system are the perception of external stimuli, the perception of internal stimuli, and the regulation of bo ...

ingestion Ingestion is the consumption of a substance by an organism. In animals, it normally is accomplished by taking in a substance through the mouth into the gastrointestinal tract, such as through eating or drinking. In single-celled organisms, inge ...

. When the conidia is within the host's body, it begins to germinate.

Germination Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, ...

refers to the process in which an organism grows from a spore. Here, the conidia present within the body begins to produce

e, which act like the roots of the fungi as they grow and branch out within the body of the host, ultimately initiating the spread of the pathogen throughout the insect. The next stage of the pathogen's life cycle is incubation; this is the period of time between the insect's first exposure to the pathogen and the occurrence of the first symptom. Within this period the internal hyphae combine digestive

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

s and utilise pressure to penetrate through a number of cuticle layers of the host. This allows for the spread of the pathogen throughout the whole body of the host, infecting the insects

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood is com ...

and tissue. The fungal

cells Cell most often refers to: * Cell (biology), the functional basic unit of life * Cellphone, a phone connected to a cellular network * Clandestine cell, a penetration-resistant form of a secret or outlawed organization * Electrochemical cell, a d ...

are able to absorb water and nutrients from the host's body, ensuring the pathogen's survival. This initiates the third stage of the life cycle: sporulation. Within this stage, the fungal pathogen begins to

reproduce Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. There are two forms of reproduction: asexual and sexual. In asexual reprod ...

, this is done through the formation of spores from vegetative cells and budding. These spores are then released within the insect and infect the

membrane A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. Bi ...

areas within the host's

abdominal The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal ...

cuticle. The disturbance of blood flow, tissue and abdominal cuticle causes the pathogen to enter its last stage of its life cycle. In the host, the appearance of this stage is apparent due to abdominal swelling creating a striped pattern that remains even after death. The last stage of the ''Entomophthora'' life cycle is

mummification A mummy is a dead human or an animal whose soft tissues and organs have been preserved by either intentional or accidental exposure to chemicals, extreme cold, very low humidity, or lack of air, so that the recovered body does not decay furt ...

of the cadaver, in which this stage causes death to the host. The pathogen has interrupted and overtaken the host's main vital mechanisms for survival, so the host's body is no longer able to function normally and defend itself against the pathogen or any other threats. The

mycelium Mycelium (: mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Its normal form is that of branched, slender, entangled, anastomosing, hyaline threads. Fungal colonies composed of mycelium are fo ...

– a group of hyphae- is then able to grow within the brain, controlling the behavioural aspects of the fly. The infection of the fly's brain allows the pathogen to gain control over the fly's movements. The pathogen commonly forces the host to locate itself on a high point of a surface, straighten out its back legs and open its wings. This allows for the hyphae to maximise growth within the body of the host causing death. Once death has occurred, the pathogen then releases its spores out into the environment to allow for

and reproduction once again. The position in which the fly remains ensures that the release of spores is dispersed as widely as possible to ensure transmission to another insect.

Reproduction

Reproduction refers to the process in which an offspring is formed via

asexual Asexual or Asexuals may refer to: *Asexual reproduction **Asexual reproduction in starfish *Asexuality, the lack of sexual attraction to anyone or lack of interest in or desire for sexual activity. **Gray asexuality, the spectrum between asexualit ...

reproduction or sexual reproduction. Asexual reproduction involves one parent, producing a genetically identical

offspring In biology, offspring are the young creation of living organisms, produced either by sexual reproduction, sexual or asexual reproduction. Collective offspring may be known as a brood or progeny. This can refer to a set of simultaneous offspring ...

, to the parent cell, whereas sexual reproduction involves the meeting and

fertilisation Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a zygote and initiate its development into a new individual organism or of ...

gamete A gamete ( ) is a Ploidy#Haploid and monoploid, haploid cell that fuses with another haploid cell during fertilization in organisms that Sexual reproduction, reproduce sexually. Gametes are an organism's reproductive cells, also referred to as s ...

cells in order to produce a

genetically Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar workin ...

different offspring. Fungi type organisms reproduce asexually through the release of

diploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Here ''sets of chromosomes'' refers to the number of maternal and paternal chromosome copies, ...

spores. Spores are micro-unicellular cells that are released and dispersed into the environment in a mass of numbers to increase the likelihood of further development and growth of the fungus. As spores are very small in size, they are easily moved via environmental conditions, that being wind, water, or even on an animal's fur. These spores will find favourable conditions and successfully flourish, develop and grow into the structure and body of the fungi. Development of the fungus via spores is initiated through germination; this marks the beginning of fungal development. Spores will begin to develop filaments called hyphae; these are root like structures of the fungi as they branch out into the environment absorbing any available water and other nutrients required for survival. Groups of hyphae will interconnect, forming the main fungal body, the mycelium. The fungi will soon develop a

sporangiophore {{Short pages monitor thumb , right , A photomicrograph of a sporangiophore