Biology 322 Fall 10 Wasp Geetics This experimet will explore the geetic priciples of complemetatio. You will set up various crosses, ad maage the life cycles of the model orgaism Nasoia vitripei i order to address the followig questios: Wild-type eye color i Nasoia vitripeis is a deep reddish-brow. You have isolated two ew mutatios that result i scarlet eyes, st M ad st N. Is either mutat strai a ew allele of the st DR gee, previously mapped to chromosome I? Or a mutatio at aother geetic locus that results i the same pheotype? Determie the set of crosses that would best address these questios. You will be required to show meaigful results i the F1 ad F2 geeratios. Be sure to read about sex determiatio ad life cycles i wasps (below) before you desig your experimets. Pheotypes Wild-type eye color: dark reddish-brow Mutat eye color: scarlet (st) Strais that we will be workig with: st DR st DR is located o chromosome I st M scarlet eyes st N scarlet eyes st + wildtype eyes Itroductio to the wasp Nasoia vitripeis Nasoia vitripeis is a solitary wasp which parasitizes diptera pupae. This species is easily reared i the laboratory o Sarcophaga pupae at temperatures ragig from 15 o C to 30 o C. The geeratio time is similar to that of Drosophila melaogaster: ~ 10 days at 28 o C ad oe moth at 18 o C. Male ad female pupae ca be held at 4 o (o meaigful developmet). Eclosed males ca be held at 4 o if they have bee fed hoey water for 24h. The adult female drills ito the host puparium, feeds o host fluids ad deposits her eggs. The larvae feed ad pupate o the host pupae. Virgi females are typically collected by dissectig Nasoia pupae from the host pupae before the former have eclosed. If allowed to eclose iside the host pupae, the adults gaw a hole through the puparium, emerge ad mate. Males average 2 mm i legth ad females 2.5. 1
Hadlig Wasps Steromicroscope use icidet light rather tha trasmitted light use white stage plate Rate of Wasp Developmet we have a 28 0 ad 18 o icubators, pupae ca be "held" at 4 o effectively stoppig developmet hydrated, eclosed males ca be held at 4 o for up to a week The Tubes cap with cotto balls, make sure there are o "tuels" or creases that might allow the wasp to escape store i plastic baskets, wrapped with "stockigs" Light females must be i cotiuous light after eclosig i order to lay eggs that will develop ormally ad ot eter diapause this is ot ecessary for males Matig Potetials female wasps start matig ~ 24 hr after eclosig males are at sexual "peak" ~ 24 hr after eclosig ideally, eclose, hydrate for oe day, chill at 4 o Movig Wasps chill your males for ease of hadlig (4 o ). They wake up fast. tap the wasps to the bottom of the tube before removig cotto Matig move oe male wasp of the correct geotype ito a tube with the correct female. Watch to esure matig, if after ~ 5 miutes, o success, add a secod male, etc. oce matig has bee accomplished, add two Sarcophaga pupae (careful ot to break the pupae with your forceps). males will die off i a couple of days females will lay eggs i the pupae ad will also suck pupal juices 2
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The predomiat mode of sex determiatio i the order Hymeoptera (bees, ats, wasps ad sawflies) is characterized by haplo-diploidy. I the simplest versio of haplo-diploidy, fertilized eggs produce females ad ufertilized eggs produce males (see figure ext page). As a cosequece, females are diploid ad males are usually haploid ad o heteromorphic chromosome pairs ca be recogized. =2 i the followig figure. =5 i Nasoia vitripeis. Life cycle of bees ad wasps ufertilized eggs develop haploid (="mooploid") male adult mitosis mitosis ova 2 meiosis fertilizatio 2 female zygote diploid adult female mitosis 5
Experimetal Cross Plaig Strais that we will be workig with: st DR st DR is located o chromosome I st M scarlet eyes st N scarlet eyes st + wildtype eyes Questios to ask your self: 1. Is the mutatio recessive or domiat? How do you test for domiat/recessive gees? 2. How does complemetatio aalysis deped o whether the gee is recessive or domiat? 3. For two gees, diagram the crosses ecessary to determie if the complemet or ot, give they are both recessive. 4. For two gees, diagram the crosses ecessary to determie if the complemet or ot, give they are both domiat. 5. For two gees, diagram the crosses ecessary to determie if the complemet or ot, give oe is recessive ad oe is domiat. 6. Does the sex of the paret carryig the mutatio make a differece? Does the sex of the progey make a differece? Ca the haplo/diplo system help you make ay shortcut? If so (ad hit), it is so, how? 6